The Ackley has slightly more case capacity than the watts, which means that it could preduces slightly more velocity in the same length barrel, but the difference will be less than 50 fps.

It's like comparing two 1/2 ton trucks, one with 300 hp, the other with 305hp. Sure, one has more power, but they are for all intents and purpose the same deal.

The difference in recoil will have everything to do with stock shape, and gun weight.

Does it really matter at this level?