Ok. I get why you have to log in and have the always online thingie. Its to get rid of cheats and whatnot.
But seriously... i am now downloading Titan quest from steam, while playing diablo 3.. Alone. Singleplayer... But what is this. Its unplayable due to lag... from downloading... in a singleplayer... Makes sense
I hope this wont be a issue in the full release...