I play the left dash on soft greens to control spin on approach shots, and the prov1x on firm greens to get a little more spin. The left dash is about 1/2 club longer, and releases more on chip shots.

I currently play ProV1x and I still have a goodly stock of x's from the last 4for3 drop.
My Titleist fitter suggested Left Dash on my GT fitting... From the comments above, she might be on to something.
My Pro stocks them, so supply is not an issue for me - just need to shift myself and get some to test!
JT

I would really like to try out the left dash as well. I have really enjoyed playing the AVX this year. Recently went with a ProV1 for a tournament with really hard and fast greens. I am surprised we have not seen an update to the left dash in all these years though.

Professional Titleist Ball fitting - ProV1x left dash. Bought a dozen.

Ace #6 with the first ball from the first sleeve - must be right for me.

Now I have some personalized brand new balls from the loyalty promotion that I need to sell ...

Congrats on the Hole in One!