lets look at this as which method has advantages and which does not.
1. setiing off the shaft - does nothing but get the rear ujoint close to 0* at launch. does not aid in preventing vibrations nor does it phase the front ujoint to the rear one. does it have an ET adavantage? possible I guess but so small I bet you couldn't tell the difference.
2. off the motor/tranny center line - has no disadvantages, aids in preventing vibration. phases the ujoints, helps prevent tail housing failure (YOU DON'T BELIEVE THAT CALL ROSSLER).
it's a given that the angle changes from start to finish. the question I ask is why would you not choose the method that has more advantages?
lets see, spicer, caltrac, rossler, recommend this. why?