I have been running dungeons with my friends who are currently 4 to 6 levels ahead of me.
This means I'm usually several levels below the intended dungeon levels, however as I play the healer role we manage to get through these quite successfully.
I have noticed though that I do not get experience from mobs dying in the dungeon. As such I find that it is quite hard to catch up to my friends levels (they do get more time to play which also doesn't help) because they will be gaining experience during the dungeon run and I won't be. To counter this somewhat my friends have been letting me open any locked chests we find (I do gain experience from them) and the initial dungeon quests themselves give me a big chunk of experience and a skill point which is great.
Is anyone else finding this? Is it intended that characters outside the recommended level range receive no experience for running them? (I can understand why this would be for higher level characters, but I'm unsure why this decision would be made to deny lower level characters experience).