Well, I'm not going to say Eleaf is a quality manufacturer. But, year old istick 20W is still going. 3 istick 50Ws from Feb are still going. Year old Lemo is still going. I just was piffed another Lemo that was supposedly defective and its working fine. So I haven't had any issues myself. One istick 100W has very rattly buttons, and the other has slightly rattly ones. That's not a dealbreaker for me for $30 each.