Very happy with the improved performance of the G56 pipes and intake with standard ECU. The sound output is significantly less than MMC1 pipes, but is this currently available? Fitting to an older 2012 car, the cost difference is not that great because one would need new brackets for the MMC1 as well.
Tim
Fitting MMC Stage 1 to a 2013 or earlier car you need new mounting brackets, as Tim says, and new heat shields which are mounted on the brackets rather than the silencer. When I fitted mine it added about £450 to the cost and made it similar total price to the G56. A few people have fitted the MMC Stage 1 without the heat shields.
