My drive came in Firmware 320XXXX and the most recent one is 322XXXX, which Kingston labels as an Urgent update. This meant that I had to upgrade the firmware out of the box. It didn't give me problems with the firmware it came with though, and actually my Windows 7 x64 installed easily without a hitch on the previous firmware. Remember guys, to fully access its potential you must enable AHCI (not IDE mode) in BIOS and your motherboard must support 6gb/s SATA 3, although it can still run on IDE and SATA 2 albeit slower than its potential. In fact, this drive is plug and play when installing Windows 7 32 or 64 bit.
PROS:
Incredibly fast read speeds. CrystalDiskMark shows 500MB/s average for me. I get WEI rating of 7.9 for Disk Transfer Rate.
CONS:
Write speeds is not as advetised for me. I'm getting 160MB/s average. I've tried upgrading my BIOS, newest Intel Rapid Storage, enabling cache writing, etc. and still no luck. My board (Asrock extreme4) also has a Marvell controller, and that too gives 160MB/s write speeds.
This is what Kinston specifies as their advertised speed for this drive:
Sequential reads 6Gb/s 3 -- 555MB/s for all capacities
Sequential writes 6Gb/s -- 510MB/s for all capacities
For the typical user, this is crazy fast. But it is just hard to accept much lower write speeds than advertised when spending top dollar for the best computer parts.
UPDATE 12/20/2011**********
Ok, I've done some research and it turns out that my results are normal. First of all, Kingston's claims are based on ATTO Disk Benchmark 2.41 results, which uses compressible data. CrystalDiskMark uses incompressible data by default, which are more closer to real-life applications. When transferring videos, pictures, songs, zip fils and the such, its closer to incompressible data. After retesting using ATTO, I get 550MB/s max read and 510MB/s max write, which is pretty much the top claim. Lots of manufacturers, especially those who use SandForce controllers, like to use ATTO because it favors its performance. Comparing other review sites I see similar 170Mb/s write speeds using CrystalDiskMark. One more thing to note, the 240gb hyperx version does almost twice as better for write speeds at 300Mb/s versus 170Mb/s for the 120gb version. My rating technically is now 5 stars, but I'm leaving 4 stars because I still feel a little decieved. Dont get me wrong, this drive IS one of the fastest out there right now equal or better to the likes of Crucial M4's, Intel 510 series, or OCZ Vertex 3.
UPDATE 1/26/2012 *******
I do not know what happened, but somehow this drive has reduced its incompressible write speed from 160MS/s to roughtly 130MB/s and the WIndows WEI hard drive score is down to 7.8 rating. Weirdly enough, the compressible write speed is still a blazing 510 MB/s. I spent several days of my time and numerous reformats trying to figure it out but its still a mystery to me. I retested using AS SSD benchmark and I also discovered the Access Read Time is a paltry .200ms on avg which is like mechanical disk speeds. To be honest, I am being a little nitpicky here but again, the purpose of paying top dollar for a Sata 3 SSD was to get Sata 3 speeds. And I'm not feeling completely satisfied with this one. I'm tempted to reduce the rating to 3 stars to "It's OK" status, but if you can find a deal where its about 1 dollar per GB then its still a good buy in my opinion.