When I saw the reviews and features, I preordered two of them. They got delivered the same day, and boy the box was clean and properly packaged.

After drooling over the boxes, I plugged one in, without remembering to turn on Steam; it already worked as a mouse without any setup at all. I turned on Steam, and the software updated.

Skip to present day, I use this thing all over. Let me tell you some crazy things you can do with this controller!

* Program any button to any xbox 360, keyboard, or mouse functions (including multiple, e.g. Alt+Tab)
* Program independent (horizontal / vertical) (sensitivity / axis inversion)
* Select commonly used community created layouts for Steam Games (and tweak them yourself!)
* Configure your controller for non-Steam games
* Grab buttons (Ring Finger / Pinky Finger)
* 2 Touchpads (can be mouse, joystick, anything in between, as well as DPads, WASD / other key configurations, screen area selection (e.g. minimap), hotkeys (up to a 4x4 grid, I believe), /and more/!
* Standard xbox-feeling layout (left / right movement, joystick below, grips, and gyro may take some learning, and ABXY buttons are considered small by many)
* Haptics! What does that mean? It means you get rumbles of vibration feedback based on activity, independent of trackpad and joystick programming. E.G. Left trackpad could have no haptics, joystick (left) strong haptics, right trackpad low haptics, and gyro medium haptics! Wow!
* Gyro capabilities: That's right, you can select yaw or roll and start using this baby as a steering wheel. Or, to control movement when a certain button is held. Want both? Do both. They'll be independant controls, and easily programmed. Want to make that gyro function control a mouse? Be my guest.
* Mode Shifting: This one's going to be a mouthful to explain. Basically, you can make the A key change the B key to another key. Or, the right trigger soft pull change your mouse sensitivity to low while changing your scope button to your fire button, while enabling gyro and turning the mouse trackpad into a dpad on full pull, with your melee button becoming a quick unscope button... Or however you'd like.
Let's do another example: You want your left trackpad to act as a trackball mouse with a deadzone, and the horizontal to be more sensitive because you have two monitors side by side acting as one, giving you a super wide resolution. Then, you're playing a game with 16 different hotkeys that you need to program, without reaching over to another device or your keyboard to try and remember what they are... And you want to program icons for them as well. You can make any button on the controller switch the mode of the trackpad to the hotkey selection. This goes for either trackpad, meaning it's really on you to come up with whatever you're comfortable with using. Any layout, this is the most capable controller.

The possibilities are endless, and all you need is to program it once in Big Picture; no, you don't have to use big picture to play your games, only to program the controller. It works in that game the same way after you program it, and you can save different layouts and switch at the push of a few buttons whenever you'd like.

The only downside to this controller that I can find is the learning curve; otherwise every individual is entitled to their opinion of how good this controller is. If you're looking to replace that keyboard and mouse, become a couch gamer, up your gaming capabilities, play around with a $50 toy, or just show off to your friends, this controller is the bomb dot com.

To this day, I've probably put a solid 50 hours of use into this, and it's at 100% battery life... with two AA batteries. That's right, two AA batteries, 50 hours use, and 100% battery life.

Not sold? Let me tell you another thing about how frequently they're updated.

You might know that these just came out, less than two months ago. Well, the Gyro function, the Hotkey Trackpad function, and the Area Selection function... Those are all new in the last update from a few days ago. New, as in, they completely added a Gyro function that didn't exist previously, just in the software alone.

This thing is perfect in every single way, as long as you don't mind struggling to learn a new controller for a bit. I'd say it's well worth every cent.

I was NOT paid to write this review, nor given anything at any discount nor for free. I preordered these with my own money, and don't regret a second of it.

What an incredibly versatile controller! Easily dwarfs the usability of any other controllers I've used. I have been using it for five weeks now. My hands are a generally medium glove-size, and I hold my controllers the way you usually see, with my pointer fingers on the triggers.
Strengths:
-It can be used as a wired or wireless controller.

-It is fully configurable, down to how each button and trigger acts and feels (haptic feedback).
The steam interface for changing how the controller acts can be accessed through Steam's Big Picture mode, and therefore in game. They seem to have implemented nearly every functionality that I hoped, and many that I hadn't even considered.

-Each input can be configured to feel like it has a texture due to haptic feedback. When I press my A/B/X/Y, I have them kick the controller slightly. When I use the left-pad as a joystick, I can feel how strong the joystick is pulling back to center. I can feel the heavy clicks of a scroll wheel if I set the touch-pad to act like one. It's something you need to feel to really get what I mean.

-Touch Menus. You can set either touch-pad to show up on-screen as an additional graphical overlay menu of actions that you can configure to do whatever you can think up. I set my touch menus to select crew/weapons/drones, etc. in FTL. That's 16 keyboard shortcuts that I put on one touch-pad. You can even add icons and text labels to the selection menu. You see it in your game and you can adjust the size, position, overlay, color of the buttons, everything! It has been invaluable for FPS's that have more than three guns. As an example of what this looks like, I've attached a photo of the FTL touch menu I just made that accesses all the ship power and menu functions.

-Those wacky buttons on the bottom of the controller
I honestly have been hoping controllers from every console would implement snappy paddles for a long time. They're incredibly useful, and if you don't use them, just un-bind them. I use them as boost and handbrake in most racing games, and as jump and crouch in most first person games. It has always been very difficult to both boost *and* handbrake at the same time in Rocket League, but now it comes naturally to me thanks to this extra set of inputs.

-Analog Triggers with a Digital Click at the end of the pull. ("Dual-Stage Triggers")
The Game-cube controller was the best feeling triggers before the Steam controller because of this feature. The Dual-shock had bad ergonomics, and the Xbox 360 controller's triggers always felt a bit weak and limp to me. The Steam Controller has really, really clean and snappy feeling triggers. There is an increasing resistance as you gradually pull in, then at the end, there's a snappy thunk that takes slightly more resistance. It's like there was a button at the bottom of the trigger. And to top of how good it feels to use, you can bind the soft-pull and end-click to do different things! I made the soft-pull slow down my aiming in FPS shooters so I can aim more precisely, then the end-click fires the weapon! I just discovered today that you can assign haptic feeling to the triggers too, so if you just bind a button or a key to a soft-pull, you can have the whole controller 'thunk' when you pull it in slightly. It's really helpful, and feels good to use.

-Impressively accurate Configurable Gyroscope
This was a feature that I didn't even realize the steam controller had until I started playing around with it. When I found out about it, I didn't think it would be too useful, but after seeing some uses that other people had come up for it, I use it often. In Counter-Strike, I do most of my aiming with the touch-pad because it feels intuitive, but when I want to aim just a tad right, I just keep my finger on the touch-pad, and move my controller a smidge towards the right. The gyro controls are so accurate and intuitive, I can control my automatic fire-spread, which is a level of precision that I can't achieve with anything else other than a mouse. Same story with the haptics, they got it spot-on. The controller gives me tactile feedback on how much I'm adjusting my aim using the gyro controls.

-Steam is releasing daily updates to the beta and adding incredible new features every day.
Yesterday they added a way for a regular WASD movement to feel analog if you are using the joystick! It's incredible that they are adding usability features almost every day at this point. They even added the feature that I requested via their feature request forum!

Problems:
-It's different! I'm scared of change!
This is the most common complaint I've seen. You're going to have to get used to it, just like any other controller. The button and touch-pad layout is something you haven't used before. It'll take ~5 days if you use it a couple hours a day and look through the simple configuration menus.

-You need to tweak profiles to suit the game you are playing:
For instance, to get the full experience out of playing Battlefield, you'll need to make the right touch-pad act like a mouse, while the rest of the controller acts as a gamepad. Or, if you're playing a flight game, you can set the gyro controls to pitch/yaw/roll control your plane while based tilt the controller (if you want). Or, you can do something completely wacky as long as it feels intuitive to you.
Fortunately, thousands of other people are doing the same thing, and publishing their favorite controller layouts through the in-steam editor, and you can just browse for one you like, and hit apply.
Some games are more difficult than others to figure out controller layouts for, but there is a large community of other people who are also figuring it out, so help is available.

-The shoulder buttons take a little too much pressure to click, so I often bind my shoulder buttons to the paddle-buttons so I can reach them more easily.

-There are a couple bugs
All three minor bugs I have reported has been fixed within a week of my report.

Summary:
It takes getting used to, but after day five, you'll be complaining about how the Xbox controller has soggy-feeling triggers and doesn't let you aim right.

I was vexxed at first by my thumbs going to the wrong place thanks to using an xbox controller, I was concerned by how different the inputs felt, but after going though the menus and making my own controller configurations for games, I don't think I can go back to any other controller. This really is the best performance you will get out of a control device of this format. The more I use it, the more I can see how much thought and experience went into making this piece of hardware.
I honestly cannot express how fun this controller is to use and configure. It takes some getting used to, sure, but the payoff is fantastic. It lets me use a controller like I always felt they should be used. After I get a game all set up, I finally feel like I can forget that I'm using a controller, and really play the game, not fight with the controls.