Hi Mike

I'm interested in this too.

Every time I speak to a pro they claim for example, that a Pro V1x is designed for swing speeds in excess of 106mph and a Pro V1 for those under this swing speed. Titleist don't claim this anywhere I've seen. 

Judging by your distance I'd suggest your swing speed was <106 and so in principle a softer ball is a better option to help you compress it more, transfer more energy to the ball and send it further.  The way Titleist design their balls is to maximise distance and build in spin control for around the green, which is the key to choosing a ball imho.  

I play a Pro V1 and I'm in your category (I carry the 7 iron 155), but have a swing speed below 106. I love it. 

My advice, try them all out and play with what you're comfortable with and what gives you best control around the green. You'll need deep pockets for brand new pro vs though.

cheers

mike