In extremely hard hits (hitting the first turn corner dot full speed, going about 3' in the air and slamming it into the outside wall when landing, etc...) I've tweaked it a little bit, but all I've ever had to do was loosen up all the bulkhead, topdeck, and shock tower screws, let it sit for about 5 minutes, then re-snug them. Good as new everytime. I've only busted one steering block, and I didn't glue my first chassis, so eventually it split apart at the front bumper.
As far as the car accelerating, I think the TC3 still has a slight advantage, but the XRay can usually carry more speed through the corner, and even the two out under acceleration. In Mod class, I think the XRay can accelerate as well as anything.
I run both rubber and foam, the car is absolutely great in both Mod and Stock foam, in rubber classes I think it could almost use a little more lateral chassis flex, but it's an extremely capable car as is.