Before I start, a little background. I have been messing around with DJing for about 3-4 years now and haven't gotten serious until the past year. Some would say I'm not a 'true' DJ as for a while, beatmatching was a bit out of my reach, and scratching wasn't something I was big on. Before I got this, I had a Numark Mixtrack Pro. It served as a good beginner controller and suited my basic needs for what I was doing. However, my DJ program of choice became Traktor. I had tried Virtual DJ and Serato DJ, but didn't like the options I had with those programs and the cost of them was a bit too high for my situation back then. So I picked up Traktor after having a few friends that had used it. After working with Traktor for a few years, I decided I needed an upgrade from my Mixtrack Pro and ideally, something that would take advantage of more features Traktor had to offer. After doing extensive research on my options, I decided on this controller as my main one for my DJ rig.

This is an amazing controller. It gives you full control of the 3 band EQ, Gain, filter, cue, volume, and what decks will be receiving effects for all 4 decks. Setup is quick and easy, just download the S4 drivers with the Traktor service center and you are good to go. You have a good range of inputs/outputs so you can use other accessories like vinyl turntables, CD turntables, or even an mp3 player if you want a backup in case of a computer crash. There are 2 outputs with independent volume controls, so you can have one as your master out and one for booth/monitor speakers. There are also MIDI ports if you need them.

The jog wheels are nice and responsive. if you press down on the platter, you can scratch, and if you move the wheel from the sides, it functions as a nudge for beat matching. The only downside is you do not have any idea 'where' the wheel is like some other controllers(no display inside the wheel, led lights on the outside, etc) so you will have to keep your eye on your computer screen if you need visual cues for scratching.

Each side of the controller has it's own loop control just below the jog wheel, and it is quick and easy to create a loop on the fly and exit out of them with just a few pushes of a button. It is also quick and easy to alter the size of a loop once it is created. Further more if you have remix decks available, you can record a loop and push it to a remix deck so you don't have to take up an entire deck for a simple loop.

As far as the performance pads go, the top 4 buttons are play/stop buttons for remix decks and 'fast forward/backward'(will jump you ahead or back in a track quickly, nice for quickly finding a specific spot in a track) for regular tracks, that means for cue points/remix deck control, you will only have access to 4 slots... As you can see from my picture, I have other controllers to expand that for my sets, so it isn't a big deal for me.

Each jog wheel and associated loop controls and performance pads can be switched to the other deck on its respective side with just the touch of a button, so you can easily control 4 decks and still have the same level of control deck to deck. There is also a loop recorder independent of the track level loop controls, so you can record a live loop and have it at your fingertips for future use, I have not tried using this yet however, so can't speak to how well it works.

The entire unit is of sturdy construction and feels like it can take a beating. The nice thing for me is it is just a little bigger than my previous controller, so I didn't have to account for a significant change in size. All the knobs have a good smooth feel to them as you turn them and each has a center 'notch' so you can easily bring them back to center. They are all rubberized so there is little worry about your fingers slipping while using them. The sliders are all smooth and offer varying levels of resistance. The crossfader has next to no resistance and it is quick and easy to manipulate. The tempo/key sliders have a little more resistance, but move smoothly. The individual track sliders have the most resistance, but are still smooth and that extra resistance makes it really easy to dial in the perfect level for tracks.

Overall it is a great controller and has exceeded my expectations. This is my first controller after my entry level one so take that into consideration when reading my review. It has already expanded my use of Traktor and given me plenty of ideas for future sets. If you are a more 'traditional' DJ this should suit your needs fine. If you are looking to use remix decks, you will only have basic functionality.

If you do not have Traktor, this unit comes with a key for the FULL version of Traktor Pro 2(Download from Native Instruments website).

I owned the Traktor S2 (old model) which was great, but i wanted to experiment with playing 2 songs at the same time (i guess you could call them "Live Mashups") but i was blown away by all the other features. im able to control a Remix deck with any of the 4 Decks, it also has an individual knob to control the LP and HP filter (it doesn't sound like much but on the S2 i had to hold the shift button and then turn the Gain knob, Instantly tying up both my hands and disabling me from doing anything else). Many people say this Product is crap because it has a SYNC button. Personally, i believe that a DJ's job extends beyond the turntables, you are also creating an atmosphere or mood for people to dance to, and basically you are what separates them from an unforgettable night out and a boring and dull night at a club/party. worrying about something as small as beatmatching is foolish, if something helps you get the crowd going nuts and having a great time, i say it is fair game!

Full disclosure: on many of the dj forums, DJs like me are not considered "real" DJs. I'm not a club DJ. I don't scratch. My dance song transitions are not always beat-matched. I don't use a lot of fx/loops/samples, except for some modest filtering/looping when I do beat match and the occasional fx. I'm still learning the remix decks. Worst of all, I often commit the unforgivable "sin" of using Traktor's cruise control during cocktail hours, particularly when I've been invited to join the guests for dinner/drinks (I still keep close tabs on the music/equipment). Btw, programming your playlist with Traktor's load and fade-out hotcues ahead of time can make it sound like you're paying more attention than you are.

Typically, I play in front of crowds mostly 40 years & older (private parties, weddings, corporate stuff, class reunions, homeowner's association parties, etc.). My strengths are an extensive, up-to-date, high quality music library (mostly iTunes 256kbps and 320kbps mp3s rips/conversions with Platinum Notes processing as needed), first-rate mobile equipment (QSC K12s & Subs, Mackie mixer (for mics and with iPods for smaller background-only applications and backup) and a love for many different genres of music. I play close attention to room acoustics and gain structure and only drive my PAs with balanced xlr signals (the S4 Mk2 requires a 1/4" TRS male to XLR male patch cable for XLR connections, not a big deal). I regularly get compliments on sound quality and music selection. I'm older (retired) and, luckily, don't rely on my DJ income to eat. I do it because I love music and I like to see people have a good time (the extra money doesn't hurt).

Sorry about the windy intro, but I wanted readers to understand my perspective. My prior controller was a Denon MC6000 (which I'm keeping for backup) and an Allen & Heath K2 that I use for more casual gigs and midi-programming fun/experience. I like the Denon a lot (great build quality), but I always found the layout a bit cramped. I originally bought it for Virtual DJ, but not long after I switched to Traktor and never looked back. I narrowed my search for a new controller to the S4 Mk2, Pioneer DDJ-SX and Denon MC6000 Mk2 (all of which, were remarkably near each other in price, if you adjust the Denon's price upward to include the full version of Serato DJ).

In the end, I went for the S4's tight integration with Traktor Pro, the possibility of exploring Traktor DJ/iPad integration, it's size/layout, and, to a lesser extent, it's remix capabilities and RGB hotcue buttons (nice touch, but not a deal maker/breaker). If the Pioneer DDJ-SX had been optimized for Traktor (as opposed to Serato DJ) and smaller (it's 6 inches wider than the S4 and 8 inches wider than my MC6000), it would have been a much tougher decision. I enjoy programming controllers/keyboards in Traktor - the performance pads on the DDJ-SX looked like fun + its build quality appears to be top-notch. As a Traktor user, the Denon (optimized for Serato DJ like the DDJ-SX) just didn't seem that much of an upgrade from my older MC6000. I know there are Traktor maps for the DDJ-SX and MC6000 Mk2 that I could have customized, but in the end I knew I wasn't going to switch to Serato (which, last I checked, was not yet optimized for Windows 8 + they seem slow rolling out updates/features,) and the S4 Mk2 just seemed like the best "fit" for me.

More disclosure: I haven't used it in a gig yet (just got it and have been practising extensively). I'm VERY happy with it so far. Nice size and weight. The control surface layout just seems more intuitive/easy to me. It worked perfectly out of the box and setup was a breeze (I already had Traktor Pro 2.6.6 and the S4 Mk2 drivers installed on my HP i7 laptop). I like the feel of the sliders and knobs/pots as well or better than my MC6000 and K2. The build quality, while not as tank-like as my MC6000, seems very solid/refined and more than adequate for what I do. The sound quality is basically perfect (to my aging ears). I have no problem rating it 5 STARS.

Observation: buying a DJ controller is not unlike buying a car or finding your so-called "soul mate" - figure out what's important to you, do your research/homework, road-test it if you can (particularly, the "soul mate") and then take that leap into the abyss and hope it works out like you thought it would (or better). Good luck.

Out of all of the software/hardware that NI makes, this is by far my favorite. I first got into DJing 20+ years ago and my goal was always that I wanted to be able to take parts of songs and create entirely new music all within the moment of a set. The S4 delivers this whole-heartedly and much more. Navigation around the console is fairly intuitive and not so complex that you need to dive into manuals. There are more advanced features that you will likely want to know so you can maximize what you can do with the S4. I really like that you can add a turntable or 2 to go all out. NI even allows you to upgrade this console and use this as Traktor Scratch with time coded vinyl. In my opinion this is the best of both the analog and digital DJ worlds and brought a lot of fun back to the art of DJing for me.