Bare Feats have done a [performance comparison](http://www.barefeats.com/pbcd.html) between 5 different 2GHz Macs:
– Dual Core G5 Power Mac
– iMac Core Duo
– MacBook Pro
– MacBook Solo (i.e. a Pro with one CPU disabled)
– PowerBook G4 (upgraded to 2GHz by a third party)
The MacBook Pro really holds itself up well, even compared to the iMac Core Duo. There’s not much trade-off in going for an Apple laptop instead of a desktop anymore! The MBP even holds its own against the Dual Core G5 Power Mac.