They are easily my favorite.
I like the Pro V1 for cool days and the Pro V1x for warm days.
I keep trying other high-end balls, because prices are outrageous, but only the Callaway HX Tour is even close to the performance of the Pro V1.
But Rusty is right. They are not for everyone. If you hook or slice a lot, you will be happier with a lower spin ball. If you want pure distance, there are others that are just as long but a lot less expensive. If you have a slow swing speed, you will want a softer ball like the Noodle. On the other hand, if you have a strong swing and want very good distance with a good amount of spin and bite around the greens, there is nothing better.