hey guys, so i recently tried the rb5 sp2. It worked really well and for 130 bux it was a steal. The car was smooth no play in parts and maybe i dare to say very VERY close to a b4.1 but it was a little easier to drive, I have used a b4.1 since i started last january and have learned alot since then about parts, setup and got to know it very well. Proud to say I am sticking with this car for now and my 8mm chassis is being done with l brace aluminum peices. I grinded the u brace were the ball studs go flat for a higher roll center we will see. But i love sloppy b4.1's it is just my type If anybody is thinking about changing please think about this post just to save some money and time, it was fun but i like my A.E!