Corsair's Vengeance K90
The K90 is the higher-end of the two Vengeance keyboards. It costs $20 more than the K60 at Newegg (though, right now, it can benefit from similar discounts), and Corsair pegs it as an ideal solution for avid fans of massively multiplayer and real-time strategy games. The main differentiator is the K90's array of macro keys: 18 of them in total, all placed along the left edge of the keyboard.
Corsair has also swapped out some bells and whistles. There are no red key caps or WASD wrist rest, but the K90 has a cool blue blacklight, and it ships with a palm rest that covers the whole length of the keyboard. On paper, the full-length palm rest seems like something Corsair should have offered with the K60. In practice, though... Well, Corsair made the thing too steep. Palm rests are supposed to prop up your wrists securely so keys are easier to tackle, but this one just doesn't do that. At all. The angle of attack is more or less the same, but it feels like you're fighting gravity to keep your wrists from sliding down and away. Good idea, very poor execution.
I like the backlight, though. It looks cool, and Corsair lets you toggle between three brightness levels or switch the thing off entirely, via a button next to the Windows key lock.
Disappointingly, the K90 uses rubber-dome switches in the same places as the K60 (top row, from Esc to Pause/Break, and the paging block) as well as in the macro keys (more on those in a minute). The company has also added little clear rubber dampers or stops to each red Cherry MX keyswitch. I'm not sure why. They make the keyboard quieter, but they also make the bottoming-out of each keyswitch feel less crisp and distinct. It seems like a step in the wrong direction—toward the ugly mushiness of silicone switches, rather than toward the clicky precision of the Model M and its tactile descendants.
I don't play MMOs or RTS games, so I didn't have much use for the Vengeance K90's macro functionality. I can certainly appreciate what Corsair has done here, though.
There are 18 macro keys and four special macro buttons: MR, M1, M2, and M3. The MR button lets you record a macro, even when the keyboard's control panel software isn't running. Just press MR, press one of the G macro keys, and enter the keystroke you want repeated. Press MR again, and boom, your macro is saved and usable.
The M1, M2, and M3 buttons effectively triple the number of macros at your disposal. A macro saved on a given G key is tied to the M button selected during recording. Press a different M button, and you can assign a completely different macro to the same G key. I suppose you could say this scheme is like having three virtual pages of macros laid out along one physical set of buttons.
The control panel software takes some getting used to, but it augments the hardware functionality. You can adjust delays, set macros to repeat, and call special commands like launching a given program, saving, or locking your PC. The software also lets you export individual macro configs as XML files, which is no doubt handy if you're ever going to switch computers or use a different K90. Quite nifty.