Initial impressions:
Starting with the cons, the voice acting is really stilted. I'm not sure what's up. Even Sephiroth, who sounded fine in Remake, is off here. I know these actors are capable of more. Was recording rushed? Did they put their B-team recording studio on this? It's like they went with the first take every time. Contemplating switching to Japanese voices just to see if I become less distracted.
Now the pros, everything else! Love that command materia is more viable now that they strengthen with your combo (Jump is especially good, use it instead of dodging!) Love the expanded music tracks. Love that you can retry battles when you die in the extra missions. Speaking of the extra missions, they're so addicting! Loading is almost instant, accumulating treasure and awards is satisfying, and the revamped areas look great. The coral caverns are an especially nice step up. I know reviewers were harsh on this aspect, but I think it's good fun in bursts.
As expected, the combat improvements are stellar. Reducing a boss's ability gauge gives a similar rush to staggering enemies in Remake. In both cases, you have a small window of opportunity to unload your entire payload. It gives battles a good tempo. Such neat design.