Why not both?  Prov1, Prov1x, Velocity, Nxt Tour.  Take your pick.

I know you want someone to tell you one or the other, but it's not that easy, look more at spin and feel. You don't pick a ball off of distance, since all balls fly so close to the same distance, if you disagree, check me against what Titleist says:

Straight from the Titleist Golf Ball Selection Page: "All Titleist golf balls are long and the distance differences between models is just 4-5 yards. This is true whether you are a high speed Tour player, moderate or lower swing speed golfer. In fact, this small yardage difference is not enough to change club selection on the approach."

I would also follow their advice to play with only one "model" of golf ball. If you are going to play ProV1x's, never play anything else. There are several variables in golf, why should your golf ball be another. Make your golf ball a constant.

Austin