I find the Jazz mould to be nice - but I really don't like how the chest can't properly lock in and it keeps flopping out during play. And they don't seem to have fixed this issue w/ Stepper or Wheelie.

Similarly I find the Inferno mould to be very nice too, but I'm not a huge fan of how the waist plate sits over the lap and makes it awkward to lift the legs up. It's not as bad as the chest issue on Jazz though. Cosmetically I find Henkei Inferno to be the best looking version of that mould. The colours on Artfire, while well executed, is just a rather bizzare colour scheme (as was the original G1 Artfire -- if I didn't know any better I'd swear it t'were a knockoff!). But Pyro would be the least best looking use of that mould (and again, intentionally so ).

...but I don't dislike either the Jazz or Inferno mould, I do think they're great... but just that those ones have their drawbacks.

The Tracks/Wheeljack mould is fantastic. A real clever way to use that same mould for two different looking Transformers.