I play on a high load server, and I get the AH lag pretty frequently, but it's never 5-10 minutes. Over exaggeration, I think? At most it's a minute, and if it gets anywhere near that I just wander off anyway.
I have the inability to log in sometimes, but not at all frequently. And generally it only happens for 30 mins at most. Yeah, it's been longer once or twice, but oh well
Blizzard's customer support has been really good, at least to me. They were doing daily maintenance for a while, and it happened to go down at 10:30pm in my prime time (South Australia), and it affected all Australians badly. So people complained and they moved it back 3 hours to 1:30am. Very reasonable, and a very good move. There's always news updated in-game (in the login screen) when there's known problems with the servers, such as inability to log in. Etc etc... They are having problems, but they are resolving them and letting people know that it's being looked into. What else is worthwhile to know?