The main issue has to do with certain perks that give N benefit per level. So you get "Disicpline" and that gives you +1 strength per level and suddenly your champion gets +21 more strength. Same for ones that involve dexterity which makes your champion almost impossible to hit and so on.
They're rare, though, and you'll get at most one on each hero.*
No, the issue is that by the time I get more than leather armor and hand-axes, my party of 4 heroes has cleaned the land, is level 12, has epic armor and weapons, and can headbutt demons.
By the way, while I understand that people want powerful heroes, if it reaches the point where relatively early in the game powerful monsters aren't a threat anymore, something's off.
The problems are the following: leveling is too fast, and there isn't enough middle-level gear compared to the awesome epic-level uber loot. I'm fine with heroes being very powerful, but it should take a lot longer.
*They are a bit too strong, granted. 1 point every other level is plenty.