One thing I've been thinking of with the standard mount when/if it take a hit hard enough to bend it means the mount takes alot of the shock of the impact, where as the bulkhead with the motor mount were to get hit by the same impact and not bend, where would the car absorb the impact?
I did find that running the standard mount useful the other day as I was having a electronic problem in one car all I did was take the motor mount out and swapped with the one in my other TC5 while leaving the motor still attached to the mount, 2 screws and 3 solder joints and I had moved a motor to another car with needing to re-mesh the pinion and spur.
EDIT: Woah this thread is moving fast.