I think it has potential but as everyone said, it's pretty mixed. Some classes are pretty fun and more fun to play than even their pve counterparts but some are totally screwed. Perhaps not in terms of how strong they are (that's true as well but I'll cover that later) but some are just really boring to play. Square had the potential to make some really interesting moves like DRK's deathgrip but some moves function the same as pve basically just more simplified to save space. I
I've only played shatter as I pvped so far just for exp but range are REALLY strong. No penalties to range and casting can't be interrupted with attacks anymore means they just nuke you and melee are back to being fodder. BLM mage in particular, as I played that the most, seems really strong. Foul's potency is way too high as anyone who is about 50% hp is basically dead.
I'd probably give the system a 7/10 so far. This revamp was very needed but they need to take a look at classes again.