I beat it with Laharl at Level 70, which I'm thinking is quite a bit underleveled. My save file clocked in at about 75 hrs (it's probably closer to 90-95 hrs counting the restarts).
I just don't like this game. I really dislike the convention of a character only getting Exp if that character deals the finishing blow. This makes leveling up magic users, and especially Clerics, very difficult. The battles are more tedious than fun. The strategy to beating a lot of the maps boils down to either simply having enough HP to survive or getting rid of the Geo Symbol(s) that change the map from near impossible to a cakewalk. For several of the tougher maps, I ended up just using Laharl pretty much solo on the map to whittle down the enemies and then finish them off with other troops that I would bring into battle for that turn. Plus, it uses a square grid, which I am not a fan of.
There is a lot of extra stuff to do in the game (leveling items, a few extra areas to open, the Dark Assembly, weapon mastery). But if you don't like the battle system, I doubt you'll want to do a lot of it.
