I know the answer to this I think! The Cats are based on awards redeemed, and when I was in London last weekend I was told (by mgr at a dif hotel) that MA fought to be a lower level in cat - I'm guessing because people have an expectation of a higher level being really fab, such as GH or CC, and MA is still basically a biz hotel, and they didn't want to deal w/ the discrepency between what they are & what is expected of a more luxury hotel.
Cheers.