I have it, have not run (opened) it yet, but i have not been hearing great things about it. Seems to be soft on top end which seems odd for a 7 port. Thinking of selling mine and getting an Rb C6BBT7 or a Novarossi 821 or a JP FX 21 B-8T for my MBX5-R buggy.
I have the new Plus 21-5k in my MBX5-T Prospec and it does fine, still wish there was more on top end but it works for my truggy.
I have a large loose track, so i do not need to much bottom, but the 180 ft back stretch requires some long legs.
I would like to see how it compares to other motors these guys have run before i sell, perhaps I will keep it. I would like to.