Without a doubt, this is one of the coolest muds around. The size of the mud and variety of playing styles available is insane! Everything flows very well and the interface is pretty intuitive, but what gets me is the detail. I have played many muds since 1992 and none have competed with this one when it comes to variety and detail.
A couple times a day there are wars that pit player vs player in different formats, but can only give you experience (and not actually hurt you). It's quite an adrenaline rush and there are some damn good players.
There are town invasions, arenas, dynamic quests, unlimited player levels and a huge host of features.
I highly recommend it.