Less depth equals more resonance.
Guys, if I'm wrong on the resonance thing, correct me.
Yea with all due respect drumac, that's backwards. By that reasoning, a rototom would sing the longest. You will get better attack on a shallower drum, but less sustain. It's all good though, one is not superior to the other, just different.
To MattM, you could always build your own set with Keller or Vaughncraft shells, any size you want. That's my next set later on this year, for sure.