Hopefully the GIAC software does a little more than 301hp at the wheels...
I spoke with Shiv over at Vishnu. The Procede V5 is already programmed to work with the DME from the 1M. Tuning should result in an increase of approx 50% of what you would see from installing the V5 on a regular N54 motor.
I would love to see some dyno results on this, as I already run a Procede V5 on my 335i