A big factor in noticing the speed of your drive, Dave, is to play games intense on your RAM. If you're paging to the hard drive (likely on high end games, even with 2 G RAM) you'll notice the speed every time it does a read or write (which is very often).
Just general file movement, you probably wouldn't notice it, tho, you're right.
Unless you're unzipping a 1200 file RAR.