There is no difference between the Encore and Prohunter...at least fundamentally. Think of a Ford and a Mercury or a Chevy and a GMC...its just the wrapper.

The prohunter is an encore, in silver, with that 'flex-tech' stock. They run about $250-$400 more than their parent Encore model's in wood/blued do. Barrels are interchangeable between prohunters and standard encores.

As far as having to re-zero, I haven't had any issues at all with my Encore. I purchased mine back in October, I went with the standard wood/blued, since the Prohunters were about impossible to find, and I am more old school anyway. Also saved me a ton of money.