My only experience with Apps phone support was when I signed up for the 30 day business trial to use the IMAP import feature. Half way through a massive import, I got an email from Apps saying that I was going to be charged the $50 yearly fee about 25 days early and then another that my account had been downgraded (I did not downgrade it). Called phone support, got a real person in what sounded like England very quickly. They were helpful and reported the issue to the engineers. They reversed the charge no questions asked, I re-signed up for the demo, and all was well.

So tl;dr the phone support seems ok.