I went from Rotor to Z2 back to Rotor also. They're nice, but they feel flimsy and cheap and that kinda annoys me.
If they had a more secure way to hold the speedfeed/lid closed, I'd possibly try one again. Somebody should design a speedfeed for it that not only uses the magnets it's designed with, but also is sandwiched in place somehow by the two shell halves. Who cares if it would no longer function like a lid, that's what the lid's for.