I dont think dealing with clients cancelled flight is considered "above and beyond". Its accepted and thereby expected procedure.
Every travel agency offers weekend support?
Global seems to have access to cheaper fares than on OTAs. I'd assume people use them when they're cheaper, not for the support.
Either way, they've been advertising for a decade and I haven't heard of any major issues. But next time send me an email and I'd be happy to pass you through to someone.