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.