It looks like the equipment that you can buy at the shops doesn't do anything. Their descriptions say that they increase character stats in a certain way, but when you equip them, nothing. In addition to that, the player character's leveling also seems to be scuffed and it looks like any stat gains from leveling are minimal.
Also, I personally find the new battle system kind of rough - you barely have any control over your characters' actions, since you only declare their intent (attack, support, special) and then they use a random skill. It gets really annoying when you want the demoness to use anything other than the mana drain skill, but she does so anyway, on an enemy that has no MP to drain to begin with. It is even more annoying, since that skill has minimal tactical applications to begin with- it looks like enemies don't use mana at all, so draining their MP only serves to restore yours, and not additionally cripple their ability to attack (at least, that's what it feels like fighting those wizards in the haunted ruins).