i drove the losi buggies for a while and they worked well.i had a constant battle with a buddy of mine who ran the B4.he was always a tick faster and it made me work hard on setup to get him.it seemed to me the B4 just worked better and didnt require much setup work to make it steer.now i just went out and got a B4 and am happy i did.it is the best car i have driven.there are a few RB 5 cars at our track and they work ok.they do have good steering but they dont run as good as the B4's do.