FWIW, I asked AE team manager Brent Thielke (most helpful team manager I've spoken with) about the different arm options and he said that they do use them as a tuning aid but tend to stick with the carbon front and B44 rears most of the time. If I remember correctly, he said the B44 arms had a "stiffness" in between the stock plastic B4.1 arms and the carbon B4.1 arms. you should also consider that the majority of the 1/10 races that the team drivers participate in are on indoor, high-bite clay.