For me it would have to be IR compatibility. Would be nice for new comers to be able to purchase an IR Taigen, Mato, Torro, etc and be able to battle out of the box. Never gonna happen, but I've seen too many people excited to get into the hobby till they learn they have to modify the tank to play. Of course your always going to have to mod motors, gearboxes, etc to be competitive but to be able to at least get on the field out of the box would do wonders for the IR side of the hobby. To me this is why Tamiya is still so attractive. Sure the electronics are getting dated, but they still provide sound ( still good enough for HL to rip off), lights, MG/main gun flash, gun/track recoil, and for the most part RELIABILITY out of the box, not to mention solid mechanics and you build it so maintenance is easier understood.