My club had a Titleist rep onsite providing customized ball fittings last week and I decided to give it a try.
The rep (Jake Hardy) and I discussed my game and what ball I was currently using (Pro V1) before we started. As for the process, Jake had me hit a 70 yard shot (60* LW), a 7 iron and finally a driver. We started with the Pro V1 and the feedback from the Trackman was suboptimal-not enough spin resulted in a loss of yardage. I also tried the Pro V1x, AVX and Left Dash Pro V1 and it turned out (backed up by the data) that the Pro V1x was best suited for my long game.
We then proceeded to hit greenside chip shots with a couple of different clubs and 10-15 putts to make sure I was comfortable with the Pro V1x.
If you've never gone through the process, I highly recommend you do-the numbers don't lie and you may find, as I did, that a different ball my be better suited to your game.
Thanks again Titleist for this type of service!