I was going to say go with the kx as the frame is similar to the gas gas so it would feel familiar but ..... they must be using aluminium like everyone else they days ... no?? I still think i'd go jap .... linkage suspension in the rear
IF you got the $$ for new you should read the Cycle News shoot-out on the KTM Suzk,Kawai & Honda there all so good they could hardly pick a winner. There shoot-outs are the best IMO