Having just beat the the main storyline with two characters (one for each of the ‘good’ endings), and having fully mapped both the Shiin and Trials dungeons, my main takeaway from this game is that the item drop rate is just too damn low.
It takes forever to farm the weapons you need in order to handle the notable difficulty jumps on Shiin floors 4 and 9, and even with good equipment the last two Shiin levels (and the later Deep Dungeon levels) are just a slog filled with enemies that do 200+ damage to the entire party, regenerate, and dodge a chunk of your attacks besides. It’s not fun in a conventional way… just a masochistic one.
Good for one playthrough, but no more unless you’re in the market for a mindless timesink.