What reputation ? Cabair don't have a very good track record for customer service in the U.K. - check previous threads regarding this organisation .
Interestingly , I was recently refused entry at MCO whilst using an M1 visa on the grounds that it was only valid for entry through MIA . Told to go to the back of the line & complete a Visa Waiver form . Was then admitted by the same INS officer . I didn't realise that the visa was port sensitive , my mistake , however it does make a mockery of the current visa regulations .