Under golf balls, Titleist does a good job comparing.
The V is softer feel, mid-flight
The X feels firmer, launches higher, best spin on short game.
They are close in distance. V will descend slower and roll a little more.

Important to try both green to tee to see which works better around green and which hits your visualized launch window. Not that one is better but which is your preference.

The biggest difference are as follows:

1. LAUNCH ANGLE: ProV1 launches lower than ProV1x which launches higher
2. SPIN; Prov1 has slightly less spin than ProV1x with iron; Both have low spin off the driver; Short Game Spin - ProV1x has more spin
3. FEEL; ProV1 feels softer than the ProV1x which feels firmer
4. LOOK: ProV1 has all Black Lettering and ProV1x Has Red Number and Black Titleist Logo (just aesthetics so you can tell the two balls apart without looking at the side model name)

Basically that is it! Here is a link to some discussion on the Titleist website - www.titleist.com/.../pro-v1-pro-v1x-or-avx-comparing-the-best-golf-balls-for-your-game

Cheers, Chris

If you would really like to truly know what the difference between the Pro V1 and Pro V1X is, I strongly recommend on-course testing.

You can buy one ProV1 sleeve and one ProV1X sleeve.

Hit multiple shots, but remember to alternate the order (V1, X; X, V1)

The ball that feels the best and gives you the best stopping power on the green is the one which should be right for you.

I have done this with my Tour Soft versus Pro V1 and Pro V1X and believe it or not in my case, there is not a lot of difference in the performance, score, feel, etc.

Why don't you do the virtual golf ball fitting consultation, golf ball selection tool (in any order) followed by an on-course ball testing (use 2020 fitting scorecard)?

www.titleist.com/.../golf-ball-fitting

As Don said, at the end of the day, it is a matter of preference.