I'll drag this thread up to add that, rather than cap recharge at 80%, why not just nerf a couple of items essential in reaching 100?
Talisman of the Jade Emperor comes to mind. Reaching 100 would then leave a toon incredibly vulnerable in so many departments, a very high level of skill would be required to play.
I'm not against the 80% cap, but this might be much easier to implement in a patch without breaking other skills.
But if you are going to cap anything, please cap CtAP :-)