I am on the 360. I have the guide. I know for a fact I have completed almost 90% of actual quests. They didn't bug, and were all completed exactly how the guide insinuates. My game does not have bugs.
I have more or less 100% completion and there are a few uncompletable quests, namely the Bard quests which broke when I found the quest item before taking the quest.
The key difference is the guide. A person following the guide would do everything in the right order and hence experiences a fairly bug-less game.
X360 also happens to be the lead platform which is the most tested. So hardware related problems experienced by PS3 and lesser PCs are undoubtedly overlooked.
While I would say most people tend to overstate the extent of their bug issues, they also usually have some basis for their complains.