from what ive read and experienced first hand the more you add on to the car the more you can see the rbc's effect. looking at this chart at the top of this post it seems that the stock im did better but with those numbers it appears not much was done to the car. ive seen other charts with boosted 9th gens with rbc and with stock im and the rbc makes significantly more top end power which to me is where this car and other hondas shine. my 9th gen (with rbc, hybrid racing intake, stock tb, 410cc injectors, dw 65c fuel pump, skunk 2 headers, invidia n1 catback) made 222hp and 179tq to the wheel on the dyno. so even with a very free flowing exhaust i didnt drop torque like that graph shows in this thread. so i guess it depends on your set up to really utilize the rbc. but as it appears here if youre not going to do much to the car, the rbc isnt worth.