Not so much the strength but more about flex. the standard arms that come with the B4.2 have the most flex or twist, the B44 rear arms have less flex and twist and the carbon arms have none to very little flex. Carbon arms are more rigid thus can snap or break easier if you land wrong or hit a pipe. I recently put the carbon arms (front/rear), the carbon U brace and carbon front top plate on my B4.2 and really like the feel of it. More consistent in turning feel and overall handling.