"Those of us in the business of keeping an eye on new technologies wonder why the buzz about SATA 6Gbit/sec.
(a.k.a. Serial ATA Revision 3) hasn't been louder than it is."
"I would wait at least four to six months before plunging into SATA Revision 3 technology. That will allow prices to drop a bit and the technology itself to mature. While Seagate has packed the Barracuda XT with 64MB of cache, I believe that 128MB would be better, given the optimal speed of the interface, and I can honestly speculate that Seagate will get here.
I suspect that Western Digital will be tweaking the firmware on its Caviar Black as well. What you can't do is achieve the overall performance advantage -- which in some cases is admittedly slim -- offered by the 6Gbit/sec. drives themselves."