I bought it the day it came out and have not had any issues at all. Only thing I can think of so far is a few very short server lag issues that happened once or twice. Nothing to fret about.
I dont know what is everyone referring to as "game content" but I would think that most everything is stored on the physical disc including "game content" because the total installation is 15GB. What the servers are probably used for is to keep track of character progression (level,items,quest completion, etc...) which is relatively low data rates