I don't understand why it would be better. It most likely has the ability to handle more torque, but that would be irrelevant unless there were transmissions failing due to being under spec'd in terms of their ability to handle the engine's power.

Failures such as solenoids, actuators, harnesses, sensors, etc, are not related to the torque capability of the transmission, but are rather a result of its complexity. And I would venture to suggest that all of the various iterations of the ZF 6HP have similar levels of complexity.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue