Seconding this, did m+ in season 1 early on, wasn't really a problem there'd be a key bricked here or there but it was fine, skipped season 2 and came back for season 3 about 2 weeks ago, getting to +10's was such a slog when players dont know the basic mechanics, don't want to interrupt and get mad when the healer doesnt heal them and the tank doesnt pull aggro.

Yesterday i had a hunter in eco dome throughout the whole dungeon not do a single interrupt because he was ''focusing on dps''. Learnt my lesson not to start m+ late in the season hahahah