I've spent quite a lot of time there as a ghost, the mages are powerfull, as it should be. But not overpower'd.
You can never appreciate a monster till you have a player/dm backing it, AI doesnt even break even on glimpsing what some monsters are capable of.
As for the mages, they have two pre-buffs on, they buff up more once folk start rampaging their way towards them.
I would like them to use more offencive spells other than their epic ones, fireball, haste, firebrand etc. It'd be a pleasant change from having Timestop then a crazy 100+ dmg spell hurled at you.
Also, they attack each other once getting caught in each others timestop. Never seen them actually kill each other, by then they've kissed and made up and decided that my arse is worth kicking.
As for the loot, it is very good in comparison to other places, the only problem is that not everyone can get a piece of the pie. 2-4 'great' toys, its a party dungeon, i've gone there with parties ranging from 4-8+.
Toys are just bonus's, as a player i smack myself with a proud message for seeing the place threw...aslong as i havnt died when turning each corner.
I say leave it as it is, i'm not sure what the xp is like, havnt had a proud message for a long long time. Might give em freaks a visit soon.