IMO, the MBP has a better keyboard and a better typing experience but the left palm rest gets a bit warm which can be distracting.
The MBP has a metal case. I've 'sparked' a few times touching it.
The MB and the 15" MBP weigh pretty much the same so the MB 'feels' heavier. I get the 'oh, that's heavier than it looks' feeling whenever picking up the MB. The MPB 'feels' right.
And, of course, the MB doesn't have a ExpressCard/34 slot, or a firewire 800 port.
All in all, for me the MB is prettier and cooler to use, but for serious work I prefer the MBP. Just my opinion.