Customer service isn't a cost center. It's a value creator.
I have similar probably-irrationally-high opinions of In-N-Out Burger's operations.
I've had such excellent service for so many years that even when I have an objectively __terrible__ experience [0], I end up writing it completely off as a fluke, or an inexperienced or frazzled employee. I actually reflected on this the last time it happened, and even recognizing this I still think highly of their service.
They get customer service so right in so many directions that I almost feel bad exposing the rare instances that my visit hasn't been flawless.
0: Last week, in the same visit to the drive-through: "No, I didn't order those [3] shakes. I actually ordered two fries." They eventually got me the right things, and my burgers were right, but I've had that wrong too before. Almost never.
The yardstick for measuring the potency of a corporate culture is consistency over time.
Back in the day when they were reselling AT&T DSL (which they are doing again, I hear), it was a big bonus to get AT&T DSL at the same price, but not have to deal with AT&T almost ever. Let a third party deal with that and provide better service for the same cost. Win.
Full Disclosure: I've worked at Sonic.net multiple times in the past, ranging from customer support when in college, to their operations and system administration department more recently. I have fond memories of it, and count it as one of the best places I've worked, but I'm not employed by them currently.