prices are dropping like crazy, so I thought I'd post if anyone wasn't paying attention. I picked up a used set of x5680 for $500 via local craigslist, and even then that's probably a bit high (but, instant gratification). i'm only running double-channel (no 3rd chip on each bank) right now, so I geekbenched at 25,800 ish. Pretty great upgrade all things considered! Easy-peasy change on the 2010, doable but a bit more butt-puckering on the 2009.