7200 rpm is overkill. Check out the bottom of this page: http://aux.music.yamaha.com/tyros2/spec/index.html

It shows all the drives that Yamaha have tested and certified under lab condition. They are all 5400rpm drives.

I would recommend getting one of these. 7200rpm will mean more noise, more heat, more vibration, and the one millisecond advantage in seek time is definitely not worth it.