Details on the successfully completed swap along with install pictures, pricing details, and the performance increase will come in a later article but perhaps the best option for automatic N54's running too much torque has been around this whole time and provided by BMW themselves.
The Getrag DCT unit that BMW sources is used in a variety of models. If you are wondering about the torque handling capability, just look at what kind of torque F10 M5's running upgraded turbos are putting out and how the DCT transmission with upgraded clutches is holding it.
Not only is the DCT capable of higher torque capability than the ZF 6HP21 it does not have the same software issues holding it back or internal hardware capability issues. Some upgrades for the AT box only aim at making it not slip at fairly low power levels in this day and age of N54 tuning. In other words, a complete waste of time for people running big boost (or who intend to add power) and concerned with maximum performance. You know, the kind of people who read BimmerBoost.
The truth is, the DCT is the best option for high powered N54's. Not only will it hold as much torque as you can throw at it you also get a shift speed benefit. It's quite simply the best performance option and the swap alone will improve performance without you even having to add any power. The E82 1M should have come from the factory with it.
If you are looking into something like the Nizpro upgrade by the time you factor in shipping from Australia, part cost, software, install, and shipping you might as well have just swapped in the DCT and had the best of all worlds.
Look forward to a detailed article on this swap coming up soon.