I'm entering the Tower of Mysidia dungeon in FFII and I have to say I'm enjoying my time with it quite a bit less than with FFI.
A think a big feeling with that is the lack of a feeling of progression and the overall dungeon design. Dungeons are not fun in this game, which is a problem since there are so many of them and very few towns to break things up.
The Cave of Mysidia is the worst offender so far. Maze-like with lots of empty rooms that waste your time, and some fights take forever because despite spamming your best spells you still do pitiful damage, especially if it's an AoE.
Black Flans are probably the worst enemies I've come across in any FF game. They are weak to Fire and can only really be damaged by Fire (Holy can work but it's unlikely you'll have it even at level 4 by this point even if you were using it every turn since you purchased it). Instant KO spells like Break or Toad are completely ineffective for some inexplicable reason. I only have 1 Fire user and had to just make do with targeting each Black Flan one at a time (the fights with 5 of these at once are just the absolute worst), but since it was only Fire 6 it may not even one-shot them if I get a low damage roll. And despite spamming Fire for basically the entire dungeon, I didn't even level it up once. It's soooooooo grindy.
I'm planning on finishing the game since I've made it this far, but I was really hoping the more grindy aspects of the game would've been more carefully tuned in this version. It should be absolutely possible over the course of a normal playthrough to get at least a handful of spells to level 16 without needing to go out of your way to grind. It would make the game feel so much better to play. At the rate I'm going I have to wonder if any of my spells not named Cure will even reach the double-digits, and I've made every one of the main trio an attacker + spellcaster hybrid so I'm using spells nearly all the time.
EDIT: One more note. I think the spell system in this game had the potential to be good due to the sheer variety of spells you can get, but they just feel so weak and inconsistent. Outside of needing to grind up Fire, Blizzard, and Thunder out of necessity (because some encounters are nightmares without them), the following spells are really all that are needed in a given playthrough:
-Cure
-Life
-Esuna
-Basuna
-Blink
-Protect
-Shell
-Berserk
-Aura
-Osmose
-Haste
-Warp
-Teleport
The common thread linking all of these? They are all 100% reliable and usable basically everywhere. And besides Cure (which honestly will be high-leveled towards endgame anyways), absolutely none of these need to be leveled up past like 7 or 8 for them to reach their maximum utility.
This is such a small fraction of the spells you can use, though. I want to make good use of spells like Blind, Curse, Fog, or Slow, but since the accuracy for them is terrible even when at like level 7 I feel that my effort to do so is just wasted. It just doesn't feel good to cast a Blind 7 and see it entirely miss a group of eight enemies.