I had a picture floating around here somewhere in another thread of 3 well bred structures, all show champions an APBT, AST, and dual APBT/AST, buggered if I could find it with a forum search LOL. Thread may have gone kaput. I could clearly see differences in that pic.
Saying that I also have Pics of working dogs of both AST and APBT and you would be hard pressed to tell the difference, and It has not much to do with what blood/genotype they come from.
Conditioned dogs look fab.
This is just my opinion but differences can also be seen in say a field Labrador and a non working lab. Even to put this further into my perspective, a working man and a pencil pusher man has marked differences in physicality. Both men, but different physiques brought on by environment.
If you find yourself going through hell; Don't stay. Just keep on going.