The pro v1x generates less spin with longer clubs therefore more distance, the prov1 generates more spin with longer clubs which creates less distance 

In my opinion it all depends on how you prefer the feel of the ball. I have played both the Pro V1 and the Pro V1x for a long time. I prefer the Pro V1 because I love the extra soft feel off of my putter and wedges. I do however know a lot of people who prefer the Pro V1x better and I at times have preferred the Pro V1x. I would, if I were you, grab a sleeve of both balls and work from the practicing putting green and alternate balls, to chip shots to determine feel and spin with both balls and then alternate balls on each hole when playing a round to determine how you like the flight of the ball and how it performs around the greens. When it comes to swing speed I am pretty sure that it should not be too big of a factor and I think that you should go with the ball that you feel more confident over every shot because you have a different swing speed on every shot depending on the club and the swing length. 

More short game spin and control with even softer feel, penetrating trajectory for exceptional distance, and long-lasting durability.

More short game spin and control with softer feel, high launch and low spin for extraordinary distance and long-lasting durability.

For me, the Pro V1 is soft; too soft.  V1x feels solid on all shots and you can trust it to dance on the green.  Pro V1 dances just fine as well.  Seems to really be a Mercedes vs BMW type comparison 

In my humble opinion.  The ProV1 is softer and better for better golfers.  The ProV1x has a higher ball flight, lower spin and has better distance with my swing.  Really sticks on the green.  Other golfers even ask me how I make the ball stop so quickly.  I love the feel of the ProV1x, has a nice click feel when I hit ti good.  I score better with these balls.

More short game spin and control with even softer feel, penetrating trajectory for exceptional distance, and long-lasting durability.

More short game spin and control with softer feel, high launch and low spin for extraordinary distance and long-lasting durability.

For me, the Pro V1 is soft; too soft.  V1x feels solid on all shots and you can trust it to dance on the green.  Pro V1 dances just fine as well.  Seems to really be a Mercedes vs BMW type comparison 

[/quote]This goes along with what the Titleist ball fitter, Lucas, told us the oprther day at the TT Outing in Dallas - the V1x offers a higher launch angle and descent angle. The ProV1x will stop quicker on the green. I've used the ProV1 for years, but may switch the ProV1x for this reason alone.

Pro v1 gives more spin therefore you get less distance, pro v1x gives less spin with longer clubs so you still have the distance you want but you also have the soft feel. I use the pro v1x and average about 295 or 300 with my driver but can still spin it back 2 feet or so on a full short iron or wedge.