Charles - The "new car" your referring to is a conversion kit to turn the JRX-S into a rear mount car thus giving it more rear traction. Losi are unsure as to whether they are going to produce this conversion kit and to quote Todd Hodge "they are still in the testing stage." This said, a few of the drivers are still using the mid mount motor, its down to individual driving style.
Badmojo13 - How did you manage to collapse all the bearings? They do need changing from time to time and if that hasnt been done, it could explain the failure. As could using poor quality bearings. The black belt kit frees up the drivetrain no end but it MUST be used with the XL tensioner. If you have just bought the belt on its own, you will not be able to get it to fit in with the original short tensioner. You have to adjust the belt pretty accurately, too tight and it binds the drivetrain, too loose and it skips under acceleration. It is common for the belt to skip a couple of teeth under heavy braking which can give you a good indicater to whether the tension is set correctly.
Finally to put you all at ease, im still running the XXX-S while i wait for my JRX-S to arrive from USA and it is still a quick and competative car 5 years after its release. It is very forgiving in accidents and so long as you get the suspension set up correctly, it is as quick as most if not all of the newer TC's!