Yea I was asking the same question just 3 days ago in a thread I started.
7,200 vs 10,000rpm: Increased gaming performance?
I've been doing research since, and looked over a bunch of reviews. Here's the most informative one that I found comparing several of the most well renowned SATA drives that enthusiats use. It compares:
Hitachi Deskstar 7K250 250GB
Maxtor DiamondMax Plus 9 120GB
Seagate Barracuda 7200.7 120GB
Western Digital Raptor WD740GD 74GB
Western Digital Raptor WD360GD 37GB
Check it out man, great review
http://techreport.com/reviews/2004q1/deskstar-7k250/index.x?pg=1
If it's too much for you to read, it pretty much concludes that Raptors are a bit pricey, but are the clear leader in performance. Desktar, DiamondMax, and Barracude are all relatively similar to one another but get beaten in almost all benchmarks by the raptors. But you will get more than double the storrage for the same price going with one of the 7,200 rpm drives. What I have learned from my thread is that faster RPM's does result in quite noticable differences in loadings times, for say opening applications or loading a map in a game. But it generaly does not imporve performance in your actual gameplay and running of applications, things like your frame rates. So if you think it's worth it to get half the drive space, but a bit faster in loading times, go with the raptors. If you want immense capacity for the same price, go with one of the 7,200 brands above. And note that all 3 of the brands listed above are the most recognized to be the best performers for 7,200 drives. It's not like their slow. I myself have came into the same delima of choosing between the Raptor, or a quality 7,200. I chose to go with the
Hitachi 160GB 7200RPM SATA. $95, for 160gigs, and better read speeds of both the Maxtor and Seagate. Can't go wrong with it man. Sure I'll experience two or three seconds (if that) of loading time difference than the raptors. But it's not exactly slow, and I'll have a hell of a lot more space. Biggest bang for the buck bro!
Hope that helped.