I'm about to get a MacBook Pro. The internal hard disk options are 160GB (5400rpm), 160GB (7200rpm) and 200GB(4800rpm).
I don't think I need the extra 40GB. The 7200rpm 160GB disk costs £100 (that's about USD200 at current exchange rates) more than the 5400 one.
The applications I use which might benefit from a faster HD are Lightroom (hence this forum), PS3 and Xcode.
Any opinions? Would I notice the difference, assuming (not necessarily correctly) average perception and patience?
You are paying way too much - although I guess that goes with Macs. For reference, I got a 10,000 RPM WD Raptor for my PC for about the £100...
The RPMs make a huge difference, especially if you're using the disk for swapping. 10-20% performance boost doesn't sound like a lot, but think how much time you spend each day waiting for swapping, opening and writing files, and cut that by a fifth, and you have an idea. Then again, the price differential is outrageous, so it's a tough call.