, I think tying combat abilities to class and level also makes more sense.
So, more like 3/3.5/PF?
It bothers me that higher level characters aren't harder to hit--an idea which is compensated by hit point bloat instead (yeah, I get it, I have more hit points so I am "avoiding or minimizing" all those lethal blows that would kill a lesser PC... blah blah blah).
I find the idea of a defense score increasing by level. I've mostly thought about that at the low levels though, and I'm not how much it changes things at higher levels or with using a single higher level creature instead of several lower ones.