Eight-speed gearbox ZF 8HP vs. Aisin-AW AA80E, which one is better?
 

Does anyone know about gear box technology? which one is better, more efficient or more advanced?

On the Web, BMW claimed that ZF 8HP is more optimized and more efficient than Toyota AISIN AW AA80E: http://www.goauto.com.au/mellor/mell...2576C60007114A

But Porsche used AISIN 8 speed automatic transmission for Cayenne and Panamera. On Autoblog review: http://www.autoblog.com/2011/05/19/2...t-drive-review

There is a comment: "the eight-speed transmission is quicker and more refined than nearly anything else out of Germany or Japan"

So, which one is really better?