Excerpt: Just not worth the money. Honestly, the K90 is uncomfortable to type on, and only offers MX Red switches. For 139$, I would expect at least some options. Sadly, Corsair doesn't give us any options and only offers red switches. The excuse is that it's best for gaming. Well, actually the best switches are all in personal preference. Some people like browns over reds for gaming, typing, etc.
Summary: Purchased this April 29, 2013 from amazon, it's now july, now every time I hit a key it hits 3 keys instead of one, so if I hit A it presses the qaz and space. Same thing going down the keyboard. What a heap of garbage. I won't be buying anything else from corsair.
Summary: I bought this keyboard to give Corsair a chance and was disappointed that when I pressed some keys such as shift they would stick and having problems going down so needless to say I returned this keyboard and got the Logitech G710+ it is a much better keyboard if you're looking to go the mechanical route.
The first one had a wonky "L" key, the 2nd one is completely dead on day 32
26 February 2013
Summary: When it was working, I liked the keyboard a great deal and would've given a much higher rating but when I got up this morning, fired up the PC and......no keyboard. No illumination, no typing, dead-as-a-doornail dead. Plugged it into my other machine to confirm its demise. So I've hooked up the old Logitech (and I didn't realize how much I'd come to like the action of the mechanical keys until just now) and here I am to RMA it except now I'm out of the 30 day Amazon...
Summary: Downloading the recent version of firmware for this keyboard bugs the keyboard & makes the macro keys, backlight, amd volume controls all useless. The keyboard is not properly recognized by the operating system. The only "fix" is by deleting drivers and tampering with the USB ports to fake a solution. For such a technical product you'd think they would have software to match...
Summary: In short: do not purchase this keyboard. This is the only review I've ever written about a product on Amazon and I'm writing it to warn you not to buy this product. I purchased this product looking for a mechanical keyboard that could play macros. Those 18 programmable G-keys seemed pretty impressive and I really didn't need Logitech's limited LCD screen on their top-of-the-line keyboard.
Summary: can not in all honesty reccomend this item as i have both the keyboard and mouse having major issues with both. the keyboard c key led has failed and the mouse died when i flashed firmware which you are required to do when you get them they dont come to you with included software and then the company does not want you to return the item to the store which is much quicker and free instead they want you to go through their rma process and pay for shipping the return back...
Summary: In debian linux variants, (mint/ubuntu etc), G keys do not work. Caps Lock light does not work. Pretty useless for any serious linux use. Stay away until Corsair LEARNS that people use other operatiing systems than MS windows.
Summary: Have not been able to get this keyboard to work with my Asus Sabertooth X79 MB. It will not allow me to use the DELETE key at boot time to get into the BIOS. Have updated the FIRMWARE and Software to the latest from CORSAIR web site, using USB 2.0. Corsair does not have a fix for this problem, just working on it, when they will have a fix unknown. I have to use another keyboard when I want to get into my BIOS, which is not good.
Summary: Alright since my last review wasn't posted for some unknown stupid reason I'll just make this short.. First K90 I had the LED's would not work on numerous keys, returned it to Amazon got another one. Second K90 I got worked fine for a while until my D key suddenly started working only half the time and a couple other keys began to get an inconsistent feel when you pressed them compared to the rest of the mechanical keys.