I'd like a less linear armor scaling progression. I think it'd be cool if each armor style had its pros and cons, instead of one being fundamentally better than the next, once you reach the requisite level.
For example, one armor would be heavier but would offer more protection (within the respective armor categories).
One armor would be excellent for enchanting.
And maybe other nuances.
I just hate how once you reach a certain level, your armor becomes obsolete and you have to get new armor if you don't want to get killed. I also hate not having much of a choice between armors.