That's a good question. The 7200 RPM drive unquestionably has a high transfer rate and much lower seek time. But the larger cache also helps the transfer rate. . . and those tend to be more reliable drives . . . .
All that said, I would go with the higher RPM drive.
I have an HP Pavillion in need of a new hard drive. The one that it currently has died, I froze it, it came back to life just long enough to get my data transfered to a CD-R.
I am looking at a couple of drive replacements but, was wondering if a larger buffer memory was better than a higher RPM.
Which one??
Hitachi 60GB 7200RPM 8MB Buffer
Toshiba 60GB 5400RPM 16MB Buffer
The laptop is used for Internet, picture editing, graphical publications and some gaming (mainly SIMS and SIM City 4)
Thanks for any help in advance.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic