I'm only on Chapter 3. Early impressions...
I generally like the action gameplay but it is a bit like Bayonetta or something in structure - as in move a few feet, clear a load of enemies... move a few feet...etc.
Midgar is spot-on. I enjoy what they did with the environments.
The updates to the central characters are decent, with some reservations.
Cons... here goes:
The Sephiroth flashes are jarring and out of place. Not working for me at all.
The dementor ghosts are terrible.
The way Aeris was introduced was also terrible.
Some of the updated enemies are too faithful and look goofy nowadays.
The NPC characters look like they belong in a different game, especially the coffee shop and weapon vendors in the slums. Is this GTA?
Although faithful to the original character design, by fleshing out and making the city more realistic and inhabited, Barrett's size and minigun arm look preposterous. Cloud's Buster sword needed shrinking about 50%. Aeris looks and behaves in a very annoying way now.
My overall impression is I like the nostalgia, but the game is tearing itself apart trying to be different things, and a lot of those things miss the mark and fail to capture the tone of the original. And they haven't even got going with the controversial stuff.