I haven't tried the II, Dawg (see what I did there?)
I read something about possible leakage through the 510 connectors, but I don't know how accurate that is. The truth is that the II didn't grab my attention because I really liked the OG. When they dropped the red onto the scene, fairly recently, I was "hook, line, & sinker".
Well, this II looks pretty sweet to me, so if I ever figure out what else to throw in the cart, I guess I'll stick with it. Unless you're tired of your Dani Mini, and ready to unload it for a hundred bucks or so.