Iron Factory is my favorite, but his transformation is bit fiddly. I really like EX Wheeljack too, but NewAge carbots don't scale well with Magic Square carbots.
I like both Toyworld Wheeljack and Iron Factory's. Toyworld is more G1 accurate, but Iron Factory has a better looking bot mode.
I have both Toyworld's, Iron Factory, & Newage versions but prefer Toyworld's. Its a smidge too small for Magic Square size, but I think it feels and looks great with my other MS Bots. Newage is just too small and IF is just too CHUG for me.
Curious is Magic Square can reproduce the "impossiblely flatten away any car kibble" look for the legs