The X has a higher launch than the V. Dashes and dots were originally developed for competitive players to reduce the launch window but otherwise retain the characteristics. The left dash X is a lower launching window than the standard X. Puts it in between the standard X and V for a simple explanation.
Access to a launch monitor is the best way to observe the launch window and also compare the spin, ball speed, and distance to see which suits your stroke best. They are the same price as the standard X. Maybe you can swap a couple of sleeves for some left dash balls and do the standard comparison. Start with pitching around the greens and work your way to driver. With a lower launch, you might get more roll-out for more distance. You just need to decide if it improves your scoring.

It would only be "better" if it fits your game. For me, they are a more suitable ball given their characteristics.