I had an issue on the second boss of the second dungeon. One of the npcs would wait to pick up a tether until I had already picked one. They would then stand in front of mine, making me have to get a new one if I didn't want two stacks on the boss, only for me to miss it. This happened enough to wipe twice on that boss. I eventually gave up and did it with some fc members later. Because of that I ended up being really put off by that dungeon. Other than that I had no issues with the AI. I like that they have their own personalities. Y'shtola actually happened to die twice on a boss, probably not moving out of aoes, and had to wait for the healer to have swiftcast "back". The second time she got raised she said, "That was embarrassing".