Best keyboard on the market.
I've never used a better keyboard! I'm not even a gamer, but the G15 is the only keyboard I'll use. The programmable keys make life so much easier. I've got mine set to minimize, maximize, close, copy, cut, paste, enter annoying passwords that won't allow my browser to remember for me and tons more. Whenever anyone sees me using my computer they always say, "Man! You're really fast!" It's all the keyboard! Set up your macros properly and your productivity is guaranteed to increase. It is a fantastic tool for anyone who uses a PC to do work.
I also really like having a dedicated CPU and RAM monitor on the keyboard. Whenever I'm working with large photo files or editing video it lets me know when the RAM is reaching critical levels and allows me to dump it before it slows things down. Nice. CPU monitor gives me an individual graphical readout of all four cores, which is interesting. Keystrokes give nice tactile feedback so typing is a pleasure. Back-lit keys are also pretty sweet; very sci-fi. USB ports on the back of the keyboard are also a very nice touch.
It is pretty massive. It will fit in most places that a keyboard is designed to go, but it might be tight. Also, it would be nice if the USB ports were powered.
This is my second G15, the first one had issues with dust and crumbs falling between the keys and causing some of them to stop functioning. I cannot blame Logitech's design for this though, it was entirely my fault for eating sandwiches over my keyboard for several years.
I think the first version is much better than the newer G15 because it has more macro keys. I use almost all of them constantly, although the average user might not have a need for all of them.