Had the first run of '15 XB4 yesterday. I am new and crash a lot to put it into context, but I would have to say the XB4 is not nearly as robust as my B5M which I have been crashing endlessly since Feb at our track (every second Saturday). It has never broken and stopped for any reason, except when I used the steering horn that came with the servo. It never did quite fit. The kit steering horn actually did fit after all.
Yesterday I managed to pop the ball caps at the rear twice and stripped the steering horn. All in 2 races. A better horn needed perhaps?