I would definitely not want to be a new AT&T customer today as they've phased out nearly every part of my current grandfathered plan, but I've had nothing but good experiences with support.

Even last year, when they somehow lost my old messaging plan in a phone upgrade, the rep (who I didn't even have to wait long to speak with) quickly switched me back.

The moment they require me to switch to a Mobile Share plan I'm out, but until then I'm continually surprised to be such a happy customer.