Prestiging a different layer resetting all your progress is way too slow for the bonus you get. The whole progression is way too slow. I'm quitting this one, as I don't even care what new incentives are.
This is good, but needs a little more. I played off and on this morning, reset a couple times and don't see a reason to reset at this point other than to try to max some stuff. A few achievements and some higher level goals would go a long way.
From what I've figured, you when your last character dies who's level is lower than the current stage dies, then it resets. I think there's a little fudging, but if you have 2 high level characters at 1-3, and the third best character dies, it resets.
It's fine to have that as a rule, but it should be clearer.