From what I've read so far, the only noticeable difference is that they cost more. Wish I'd had some discretionary funds... I'd have bought a few dozen of the older model V1x.
It seems like ive been bashing titleist lately but the new pro v1x's are not the ball for me. I dont know if me and a friend got a bad batch of balls but out of 2 different boxes of balls they seem like they are lacking in distance and the balls are hard to control compared to the other expensive balls. Someone chime in and see if your results were the same.
Re: Titleist Pro V1x (2007 version) Golf Ball Review
Let's face it - an excellent ball at an insult price. I like all the ProV's until I look into my wallet. I will say that I don't see that much that's new about it.