The model 29-5 and later versions had real improvements in the locking system, making them stronger. I know pinned barrel and recessed cylinder are "nice" but I prefer the strength of lockup of the 29-5 and later revolvers.
A good article on the different versions found here:
I believe the SBH has been virtually unchanged for the length of it's existence, with the exception of integral scope mounts on the Hunter models. If you want to scope your handgun, I'd look for one of those.