I wouldn't know as its never really happened to me (travel too many times to mention but longest wait for bags at MAN has been about 45 minutes on very few occasions. Unless I'm just 'lucky' nearly every single time I fly, in which case I must really buy a lotto ticket!)
Honestly hand on heart never had to wait for a marsheller, jetbridge or steps have always been there within 5 minutes. Not saying iyour events dont happen as I'm certain they do from time to time, but, apart from the long depressing walk down B pier at T1 or the naff domestic arrivals corridor in T3, that's about as bad as it gets for me.
Last night I was one of 4(?) arrivals (may have been a 5th but didn't read the boards properly) and it took me no more than 35 minutes from arriving on stand to getting outside arrivals. 5 or so minutes of that was getting the steps attached, 7 or so minutes walking down B pier, 8 minutes at Border, 10 minutes for bags and then the last few minutes walking out of baggage.
Like I say, that may make me a MAN apologist, but I can only report my own personal experiences. I know the actual terminal space is a depressing, crampt and no longer fit for modern day passengers, but as we know MAN are working on that, as we know how long it takes for infrastructure projects to get moving in the UK (look at LHR T5, the late 1980's was when that was first put for discussion to the public!).
MAN is far from perfect, I know, you know and we all know. But, it does the job and with growing passenger numbers, it's clearly doing something right, as if this forum was indicative of the issues, passenger numbers would be falling with the amout of people opting to fly from elsewhere.