Let's keep in mind guys that the game is essentially unfinished, as shown by characters getting new abilities, the fact that 21F and 22F are inaccessible at this time, and the mysterious Door on 12F that is also inaccessible. My take on the whole issue...
As it's been mentioned, the game is basically broken by certain characters, such as Suika (Biggest offender, I both want a nerf and don't want a nerf) who's damage formula is atrociously high. This can be fixed by lowering her damage, or raising the HP of every boss. The problem with the latter is non-broken or less-broken damagers, such as Yuugi or Youmu, get left behind. Or, by simply not using said characters. I've said before that when I go through again on a normal playthrough, I'm not using Suika, Byakuren or Komachi, because they are the ones who broke the game for me. Speaking of Byakuren, she may be broken, but she's also one of the last characters you can recruit, so I think in all honesty she can be a little broken. Suika's brokenness is extreme, and while I don't mind her being a little OP considering the money you have to put into getting her, but she's way too OP as it stands now. Komachi I think is a accidental broken, as in they looked at her, and went "Oh, she's not that bad" then suddenly BAM in practice she's broken.
Even though, with the end game, being that far along and having your characters as developed as they are, it would kinda feel like a sham if they didn't blaze through everything in front of them. Plus, in regard to the difficulty, it's definitely easier than the first game, no doubt. But it's not easy over all. Some bosses and enemies still maintain a level of challenge: Komachi, Yukari, Tenshi(s), Mokou, Iku (please tell me I wasn't the only one who had an issue with Iku), and the 16F-19F mobs, to name the ones I remember off the top of my head. It has an average RPG's difficulty.
I, for one, enjoy the game more than I did the first one. I loved the first game, but this one isn't soul crushingly difficult and a lot more fun. Though, I'm a sucker for skill systems. And any system that gives me a lot of control over my characters' growth, IE FF8 or Disgaea.