played the x for many years and switched to the v1 this year to get more spin rate off my driver cause it was too low. now i am hitting it a little further and it feels much softer off the face and it is now my pro v of choice.im a 2.3 index and drive it in the 260-270 range

Pro V1.  It has the spin that I'm looking for

pro v1 because it gets me more spin and lets me hit it farther but if you can hit a lot of backspin around the green the go pro v1x because you will have less spin and more control.

Huge difference in my game between the two balls:

ProV1: Lots of spin, easier to stop around greens, easier to work ball right and left on approach iron shots

ProV1x: Reduced spin, straighter off the tee, better in windy conditions to control, slightly firmer feel, releases easier on chip shots around the green

Overall, each are great balls!  I use the ProV1x but decide which factors are more important and go with it!

Along the same lines, how do these balls vary from year to year?  Does the performance drop off?  I was just given a dozen Pro V1s from I believe 2008 (392 style).  I currently play the Pro V1, but would like to try these too if they aren't too old.