Did the Cranfield Msc about 8 years ago and really enjoyed it. They have good cheap accommodation (especially for marrieds)and the money we saved on mortgage/rent and rates etc. over the year basically made the course free!! Don't know the story today, but things I remember include the fact that real airline management never seemed interested in the courses, the students all came from wide backgrounds, but not airline management. However, there was a short course over a couple days, when managements were invited to participate in the airline management simulator created by the staff. They basically set the fares and capacity over an accelerated period of time and reacted to each others inputs. Funny, but they always drove each other bust by setting too low fares in the pursuit of shafting the other teams, could never resist it apparently, even though they could have co-existed profitably together in the simulation.
Anyway, in the years since then I have watched office politics and egos do more decision making than analysis and reason at airlines. But maybe that's the nature of the beast, as even the academic theory didn't fare too well when our Professor met the real world with a bang when he tried to sort out Olympic.
Overall, I would recommend people to do the MSc only if they find the subject interesting and the want the satisfaction of achieving a hard worked goal. I wouldn't advise you to do it solely for advancement and career success. That would be like doing a maths course so you can win the lottery! Do it to enjoy and you won't go wrong!