Larry

it looks like they changed the color of the outer core and the dimple design.

On this page, at the top, put your mouse on "golf balls", a menu will pop up, one of the options is NXT Tour, on the right side there is an option "other golf ball models", this option has last years model NXT Tour.

Sorry I can't tell you of real golf world performance differences, I never used last years model.

I wonder if they are trying to take the performance and characteristics closer to the ProV1x? 

That was my thoughts as well