After having badcube on hand and watched mmc version of trailbreaker, I am still happy with badcube.

Yes mmc is easier to transform but I felt badcube version looks very toon accurate for me. I think partially I don't like mmc chrome on the guns.
Overall I can see people taking mmc base of transformation alone.
But after transforming twice I didn't felt overly bugged as I did with TT tracks.

Not sure if fantoys is better but to be honest you should be fine with either one imo.