This keyboard is a 'step up' from my former wireless keyboard -- also a Logitech:
Logitech Cordless Desktop S510. While my old keyboard was nice, the K800 offered a number of significant improvements, including an illuminated keyboard and a built-in rechargeable battery. It's also compatible with the Logitech Unifying Receiver, which operates on the 2.4GHz frequency for great range and performance. Bottom line -- I LOVE THIS KEYBOARD. For more details, see below:
>>SETUP<< -- Getting this keyboard up and running was a snap. I just took it out of the box, inserted the Unifying Receiver, a teeny-tiny little USB device, into my desktop, and turned the keyboard on. The entire operation, from bringing the box inside my house to actively using the keyboard, took around a minute. This keyboard is truly plug-and-play.
>>APPEARANCE<< -- This keyboard is sleek and stylish. The all-black coloring and use of both matte- and glossy-black finish is a tasteful design choice. This keyboard, like my old one, has a slim profile... very modern and 'clean' looking. The backlit keys are amazing! This is definitely a feature I will enjoy. It's nice to be able to see the keys at night without having to have the lights on; not only does it cut down on electricity, but it lets you do work at night without having to keep the house lit up while others are trying to sleep. Plus, if you're into gaming, it lets you get 'in the zone' with the monitor as the sole light source (besides the keyboard).
>>PERFORMANCE / FUNCTIONALITY<< -- Again, this keyboard is a step up from my old one in every way. The illuminated keys (which have 4 brightness settings plus an 'always off' setting) are very nice. The programmable function keys are a bonus, but I don't typically use those. The keyboard layout is pretty much the standard, and should be intuitive for those with even a basic level of computer experience. The key spacing and proportions are good; I have large hands, my girlfriend has small hands, and we both love the keyboard. Keystrokes are smooth and QUIET, making even less sound that my old keyboard, which was already pretty quiet. The feel is that of a very nice, solid laptop keyboard... only a bit larger, and without the Laptop.
>>WIRELESS CONNECTIVITY<< -- The 2.4GHz receiver with Logitech 'Unifying' technology is awesome. Truly plug-and-play. As an added bonus, the range is FAR superior to that of my old keyboard. I can sit at the table in my dining room, eating a meal or playing cards or another game with my friends, and use my keyboard to shuffle through a playlist on the computer in my office 30 feet away, behind a wall. The extended range of the 2.4GHz unifying receiver is something users of this keyboard will definitely enjoy.
>>RECHARGING<< -- The recharging feature is great; no more worries about popping out batteries. I use
SANYO eneloop 4 Pack AA NiMH Pre-Charged Rechargeable Batteries for my devices, and a pair of AAAs in my old keyboard would last a couple months. Not bad, but it's even nicer to NEVER have to worry about batteries. The 10-day life is fine for me; recharging is as simple as plugging in a micro-USB cable to the back of the keyboard. You can do this while using the keyboard, or leave it charging overnight. Having the keyboard plugged in every week or so for a few hours, to me, is well worth the tradeoff of its light weight, illuminated keys, and excellent wireless range. NOTE that while the keyboard package includes a USB charging cord, you can use any old micro-usb charger plugged into a wall socket / power strip just as easily. Personally, I have two micro-usb charging cords plugged into my office power strip, and have them threaded through the little hole at the base of my monitor stand. I use these to charge wireless headphones, my cell phone, the K800 keyboard, bluetooth headset, etc. Very convenient, very cheap. You can find them for around a dollar on any web retail site, Amazon included.
>>SUMMARY<< -- what's left to say? I really, really like this keyboard. At around eighty bucks, it's a considerable pricetag for something as 'basic' as a keyboard, but take it from me: you will like this keyboard. The feel and layout are comfortable and sleek. The performance is great. The design / appearance is clean and modern. The recharging and illumination are key features you never knew you needed or wanted until you sit down and type with this keyboard. Bottom line: I enthusiastically recommend this keyboard to any and all users who may even occasionally wish to make use of the functionality of a wireless keyboard.