Summary: My wife and I both use the G110 keyboard, not for gaming, but for photo editing, and use the programmable keys a lot. I wanted the G510s for the six extra keys. I've purchased 3 of these keyboards so far, but have yet to find one that works 100%. Both keyboards received from Amazon had bad LCDs, with streaks below letters. The first one from Amazon had the bad spacebar mentioned in another review, as well as a shift key that didn't work 100% of the time.
Summary: While the G keys and other features are nice, the poor setup of the lowly space bar will have you beating your head against it! The space bar seems to have a narrow center actuation point and if you don't hit it dead center it will bind up mid stroke and not perform the action needed! I started using the G510 after my old G15 Ver. 1 died. If your like me, in time, you will get use to its actions and only miss spaces every 100 keystrokes or so!
Summary: Mine arrived and it's cool. It looks good, and it feels good and the product seemed almost perfect. The problem, is that it wasn't fully functional on arrival. I can't change between the three profiles using the keys, so I'm stuck on one set of macros unless I pull up the program used to switch them. That's the only problem, and I would have asked for my money were it not for the fact that I need a keyboard so badly and can't spend the time sending it back.
Summary: I have owned a G15 since the mid-90's and I have never had an issue with it. For the price of the G510, I was expecting the same quality. I thought that it was just me, but after doing a quick google search "g510 spacebar issue," it appears that the spacebar on this keyboard is horribly designed and it will quite often register two keystrokes when pressing it, resulting in many double spaces that I have to keep backspacing.
Pros: looks good, has useful media keys
Cons: spacebar consistently double spaces, headphone jack not so great quality for music
Summary: Mac users: - There are drivers for the LCD panel but they're buggy and won't initialize the LCD all the time especially waking up from sleep mode. The LCD defaults to displaying "G510." - The keyboard takes time to "boot up" and thus you CANNOT select a boot drive when your Mac starts. Holding down the Alt key does nothing. Keep this in mind if you intend to do any dual-booting with Boot Camp partitions.
Pros: Macro keys for gaming and various tasks. I'm using them to launch applications.
Cons: Keys are very mushy and took a bit of getting used to. Thought they'd be better coming from a $20 Microsoft keyboard. Single level on/off for keyboard backlighting. Would NOT buy the keyboard at full retail price and I'd even think twice about buy this keyboard at all... see summary.
Summary: Major Cons I didn't think 500 mhz / 2 milliseconds can be so slow, but it's ridiculously slow. The keys are also not very tactile, I thought logitech would be good since I've liked their quality in mouses, but no, stay away from their keyboards. Even a DELL keyboard feels and works better than a Logitech keyboard in terms of responsiveness and I'm a person that doesn't like DELL at all.
Summary: What I liked: I liked the fairly small footprint of the keyboard and all of it's features. I liked the switches used on these keyboard as well. It was the main reason, I bought the keyboard. What I didn't like: The back lighting was too dim to be useful. Most of Logitech's keyboards use a slightly larger and more dish shaped keys. I expected that from this keyboard too. Unfortunately, I couldn't tell they were different from the pictures.