Yeah, the 3x PCHP makes things a lot trickier. My main issue with 2.5 is it just makes people feel too frail to me, but I definitely understand why it's used (healers -luv- 3x, comparatively), so.
EDIT: The below is babble done while I was distracted by my dad, so forgive incoherency. I think the point gets across, but I edit enough that I'm too lazy to do it to the below. >_>
NEB: I could see end level as 50 but no lower. It felt like you were meant to be using summons that often by endgame, not that I did anyway. And I'm willing to entertain myself being overleveled but not so much as to be at 41, so. >_> No objection to your standpoint, but I definitely see it 50-55 range personally. (If anything, you get there by the final part of the last dungeon.) I take 55 since, yeah, that's where I ended up, and while better players than I (hey, NEB) can no doubt get through having far less... eh. It makes more sense to me to do 55 due to how I played through, but taking it lower's reasonable on review.