I recently upgraded my laptop to two 7200 RPM drives. VERY noticeable difference, but then I do a lot of disk-intensive work (yes, a SCSI setup on a workstation would be better but I can't log that around...
Admittedly, I believed I had a 5400 RPM drive (Toshiba specs for the Satellite 5205-S703) but to my surprise when I opened it up to do the replacement I found a 4200 RPM drive. Pretty steamed about that since the main reason I bought the Tosh in the first place was Tosh's web site saying 5205 had 5400 RPM.
Oh well. Anyway the 7200 RPM drive(s) were very much worth the price, my laptop is zipping along much faster. These drives also have 8 MB of cache (!!!).
Someone complained about the price. Read up on these new drives; not only do they use hardly any more power than 5400 RPM, dissipate about the same heat as 5400 RPM, give you 8 MB cache, make no more noise than a 5400 RPM, but Hitachi/IBM had to come up with a new head design to make it happen. In short, these things are engineering masterpieces. You get what you pay for; if it were easy or cheap others would be offering 7200 RPM laptop drives too.