This is an unbiased statement:
If it does come down to driver and setup skills, then why would anyone buy the JRX-S? Batteries are hard to solder in (I've seen belts get burnt and a guy overheated a bar which collapsed and shorted out the two cells. This would not have happened with a normal BD or SD. Also, doesn't this car have plastic bulkheads? I've seen a bulkhead snap on the racetrack before. The guy running the car just switched to his XXX-S b/c it would have taken too long to repair at the track. What about servo positioning? Is it not more difficult to set up the servo when it's closed in on 3 sides?