What I gather is: 2:2, 3:2. 4:3 (2:1 seems to give less xp than it used to do, I'll have to test it again to see) small dungeons or 5:5 medium/large (not sure about this, I stick to small). Guide mode off, and kill all the monsters and open all the passages, splitting up and taking different routes. For small, dungeons take around 8-12 minutes to complete roughly, and if you have max prestige you get from 3k-12k (I'm not 69+ so 12k is an estimate, but I was getting around 3k xp on the first dungeons) xp from going through 1-35. Apparently doing the first few dungeons with 1 complexity and working up to 6 and carrying on is faster aswell. There's some tips based on mine and a few high levels who I've been in teams with findings, a lot more research and replies are needed obviously. :P I'll try and find out more in detail by asking later.