....It looks like the Big Daddy, or is it Mother Fecker, of air intakes. gruppeM have a major reputation in the BMW world, so I would expect them to be good. BUT....You pay a premium for all that carbonfibre eye-candy!
It's generally reckoned that the filter is all important. I'm running a Carbonio with ITG Pro panel filter, so it's probably as good as a Carbonio can get. However, I wouldn't like to say how it compares with the gruppeM and would expect the gruppeM to contribute more to performance - It should do at the price!!