I was in a team yesterday that made it through 24 waves in the instance. To be honest, after we 'figured out how to do it' the biggest challenge was to stay focused enough and not do something stupid out of pure boredom (thank goodness for ventrilo and silly team mates).
At the end.. after about 2 1/2 hours or so we all ended up with a "We did it 24 times" type shirt and some random replica armor that I don't even think anyone looted that droped off a handful (literally) of mobs.
I have mixed feelings about the encounter. It is the ultimate 'bragging' rights type thing but we only got half way at about 2.5 hrs.. so that means a 4-5 hour encounter.. that is excessive.. especially considering people need food, bathroom and stretch your legs break. But, its different and for that I give a thumbs up to the designer... really long though.. or maybe I"ve just softened in my own old age.
Edit: Thinking about this later, I think that this is a cool halloween instance. I mean all of the major halloween phats are easily obtainable at all levels.. this is just something that a team of folks can do if they want.. just for bragging rights really. And being that a big part of Anarchy Online is about twinking and being "The Best" it is an appropriate thing to have someplace. We don't really have 'achievements' in this game like there are in some others.. this instance is an achievement and thus primarily its own reward.