>>80
There are multiple:
Horrible, horrible lag. No matter how good yours is (IE: mine, 40 ping), I still get people backstabbing me right in my face or 5 feet to the left of me.
You have to constantly reload the game to get into a good server full of people
Ring of Fog and Tranquil Walk of Peace makes for unbelievable cheesing in PVP.
If you want to play with friends, you'll have to fiddle with your summon sign for almost 20 minutes just for your servers to match up.
If theres anything I missed, feel free to add