I have to say I have never had an issue with the staff at MAN T3, usually very quick and efficient as long as you have Fast Track to avoid the RyanAir queues!! My only issue there is the whole family/pram lane being supervised by the same person who does Fast Track, you end up waiting behind a a family trying to sort out their kids half the time! Not the agents fault however they are just doing their job!
The security agents always seem quite friendly to me, as for the scanners I believe the situation at manchester is you dont get a choice until the new ruliing comes into effect when they are replacing the machines! I think the thoughts of the Dft (although they dont exactly cover themselves in glory these days) and to a degree in manchester is this is a ruling made by Europe that the UK is being forced to adopt rather than they agree with it!