It probably doesn't matter if you're not going to be racing on the track, but one nice thing to have on a track crank is knurled fixing bolt backing retainers (the nuts) that attach to the crank. Having never used a Shimano track crank, I can't say if they have this feature, but Campag track (as well as Sugino 75) have crank spider holes small enough that a knurled track nut will stay fixed in the spider. This lets you do FAST chainring changes because you don't need a backing retainer tool; you just unscrew the fixing bolts and the backing nuts just stay firmly in the spider. And if you use Campag fixing bolts, the allen key goes all the way thru them, so you can stack all 5 on a 5mm Campag "pregnant" wrench. If you can do this with Shimano track cranks (and I can't really imagine Shimano being so stupid that you couldn't), then you're back to square one.

The other consideration is ISO square taper vs Octalink. My preference would be for Shimano Octalink, as much as I like Campag cranks. It would really be nice if Shimano made a track crank that fit a Hollowtech bb!

Luis