* The game wanted to motivate PVP, but it did so by punishing PVE players horribly: at higher levels, dying to a mob meant losing more than one whole level, which was hard to get back.
* If you played anything but a tank, ping mattered too damn much. I like scouts/thieves. My ping stank. My experience wasn't very happy ;)
* Mandos sleep. Need I say more? Whose idea was that? I'm lucky I never got it, but it's inexcusably bad game design.
* I understand that playing evil races is supposed to be inherently harder, but it was too damn hard. My favorite moments were when the "darkies" (I apologize, but that was the slang for evil races back then) would come raid Bree and Fornost. Yes, it was terrifying for us pukes, but I loved it.
I have contemplated going back many, many times, but the first pain point I mentioned always keeps me back. I just can't dedicate that much time to a game that rewards so little and punishes so much. But I miss it a lot, too :)