Pros: Almost a week on a charge and I'm messing with it most of the day.
The lights turn on automatically and it's never a problem but a good thing. You don't have to press a key to see what you looking for, just get your hand close to the board.

Cons: Wish I could change the hot keys

Pros: design, key performance, this keyboard is the real thing for my taste with great HMI

Cons: none

Revised (03/19/2016): after some time it did not take any key-inputs anymore under windows. It worked until windows had started up. All setting issues discussed on the internet were not applicable. It is most definitly realated to a keyboard issue. SAfter afew weeks trying everything found on the net anywhere I trashed the keyboard.
Never had anything like it before. I moved back now to a simple wired keyboard that works reliable.

Other Thoughts: I trashed my still pretty new and expensive ROCCAT keyboard because this was nothing but flashy looking bulky trash. This new keyboard is the real thing for my taste with great HMI

Pros: This was a great keyboard. Simple, nice looking and functional.

Cons: The keyboard has lost it's illumination today. 4 years? If it wasn't $80.00, id say OK. Won't buy another.

Pros: Everything! Keyboard is sleek and well made. Back-lighting is top notch and sensor to dim while not using works perfectly! Wireless signal is amazing :) Battery life is the best I've ever seen in a re-chargeable device...I'm a gamer and use mine 4-6 hours a day lasting 2 weeks on charge. The battery just really amazes me. One of the best keyboards I have ever owned wired/wireless!

Cons: If you are reading this....then you don't already have this

Other Thoughts: Best wireless device I have ever owned. Would still recommend wired mouse for most games, but this keyboard is great for anything from work, play, web browsing whatever you need to do.

Again the battery is mind blowing good, I own wireless mouse/headset and have to charge every night otherwise will be plugging them into to charge while i use them next day....

Pros: Thin, sleek, has a built in battery. Lights up too so you can work in the dark. Has an off switch too to save power. The connection is USB for charging so I could charge it in the car if I wanted, heh. It has an FN key that can control Windows Media Plkayer, iTunes, etc for volume and play options and also your email, calculator, etc keys. Typing is a slight adjustment since my last keyboard was so big, but the keys are nice and smooth and easy on the fingers. There is a 40% different in typing volume from the clicking of the keys from my last keytboard

Cons: None so far

Other Thoughts: I really like Logitech components. I have a wireless mouse of theirs and the z5500 TXH surround sound speakers with them and have had them for 10 years with no issues. I got this keyboard from retail, so it won't show verified owner. It was cheaper retail too, nothing against NewEgg, I love them, just had an emergency where my dinosaur wireless keyboard that used batteries and a huge connector to my USB port completely died on me and nothing I did, batteries, cleaning it out, etc fixed it. I work at home and I game and both are perfect with this keyboard

Pros: Smooth, quiet typing
Nice backlighting

Cons: The most frequently used keys come loose, and the tiny tabs that hold them in place break. This has happened to almost a half-dozen of the keys on the board already.

Other Thoughts: Reported this issue to Logitech. They refused to cover it under warranty with no explanation.

Pros: Great KB, have several K800s that are amazing.

Cons: Rechargeable batteries came dead. Had to purchase two rechargeable AAs. Not a huge deal but annoying.

Other Thoughts: Logitech is the best

Pros: Long battery life
back lit keys
auto shutoff
has been a great keyboard for school and gaming

Cons: none

Pros: After 2 years It still does exactly what I need it to do. Illuminated and wireless, and the battery life is about what I would expect. It's got a sleek professional style without the cheesy gamer styling that you find in most illuminated keyboards.

Cons: If I'm being really picky, the key presses are too smooth? It would be nice if they had a little more "mechanical" feel with some tactile feedback. I paid $70 for mine a year and a half ago, they are now $99 which is a little too much in my opinion.

Other Thoughts: Overall it's been a great keyboard and I probably won't be looking for a new one in the near future

Pros: This is my second purchase of this keyboard, it's great if you want to use it in low light situations, it's backlit & also adjustable on the level of lighting

Cons: None

Other Thoughts: Have used this model for over a year, it's best of the best I feel. It's rechargeable, has lighting & is wireless, it can even be paired to one usb plug in. So my mouse & keyboard are on one usb. My setup:

Intel i7 5690x @ 3 ghz
ASUS Rampage V Extreme (open box)
64 gigs of DDR4 G Skill 3000 MHz ram F4-3000C15Q-32GRBB
1 terabyte Mushkin Reactor SSD
LG 3D bluray/DVD/CD reader/burner
Logitech K800 keyboard & Performance MX mouse
1300 watt EVGA PSU
Antec 1200 unbeatable gaming case full tower
32" Vizio smart tv as the monitor
Dual - VGA 06G-P4-4995-KR GeForce GTX 980 Ti 6GB 384-Bit GDDR5 PCI Express 3.0 SLI Support SC+ w/ACX BP Video Card
Windows 8.1