Well I think it would be cool if there would be a Mob arena for donors tier 4 or 5 and above. This would be a neat donor perk and I think would get more donors. To stop from people getting to lvl 60 in a couple hours, I think they should have reduced experience. So a zombie gives the group around 5 exp. It should take the same amount(or more) time to level up. It also could be opened only one day a week or you can only go once a day. I liked to go into a Mob Arena for fun. I really like the quest but I would like to have a Mob arena even If it gave very small experience to the players.