Khan Academy may have it easier, I'm sure Google won't let them down
Really, go somewhere else, spend less money and have better support.
(At the expense of, if you're lucky, Google will give you almost zero headaches)
But you can bet that if Khan Academy has a problem it will be looked into with extra attention.
Also, Khan academy receives funding from Google ( http://en.wikipedia.org/wiki/Khan_academy ), so I don't think it boils down to only having a Premier account.
Whether you believe it or not, a Premier account is what you need if you want support. You could argue that $500/mo is too expensive, but it is what it is.
What I don't believe is that the support provided by Google is good or sufficient. Based on experiences with paying Google Apps, I'd say it's not.