I think a lot of it has to do with the role you play too. Benefits of being a Tank or Heal er aside from fast queues/groups is that if something drops for you in a 4 man, there is no competition. In full 8 mans, you can either have no competition or just one other player with his sights on the same loots. Not only do you get to run content at your leisure, if it does drop, you have a damn good chance at nabbing it too.