Shaftdriven 4wd, motor position?

[Mr. Red]

Seriously, I want to know!
Can someone explain how the motor rotational direction affects the car's balance in conjunction with the center drive shaft? Or does it not matter cuz the two equals each other out?

What is the best solution? Like AE, Tamiya, HB and now caster have done. The motor placed on the right side of the centre drive shaft. Or like Durango and Kyosho have done. They have gone the opposite way. Kyosho still on the right side but facing the axle towards front instead. That will give the same result as Durango who have placed the motor on the left side.

In my book it seems like Kyosho and Durango got it right and the others got it wrong. Am I totally wrong here or does it exist some sort of truth to it?

If I were to construct a new car I would be very interested to know these things before I start. Hope you understand what I am after here.