As of current, I've only been randomly disconnected from my game once. I can understand how it can affect those who are trying to farm, but I think part of the intention behind it was to promote playing through an entire act with 5 stacks of Nephalem's valor-- not restarting act - 2 quest - 2 to spam Zoltun Kulle five hundred times. As well as balancing stress server side, of course. Though with as big of a budget Blizzard has, I don't quite see why this was something they'd want to do.