I believe my brother has it for his Slash Ultimate. He mostly uses it to monitor his temps and batteries. And to restrict the speed of the truck when he passes it to a new driver. I can't really tell you if it's worth it... And I don't know anything about performance issues. He's never complained about it.
Axial SCX10, Vaterra Twin Hammers, ECX Boost, Ruckus, Smash, Circuit, Torment, Traxxas Rustler, Slice Db, MERV, Bandit, Stampede 4x4, Blast, Sparrowhawk XB, Evader BX, Evader Bl, RC10 B4.1, Rc18B