"ride height alignment" different from alignment?



We have air suspensions. My service receipt upon delivery showed that I got a dealership "ride height alignment." How could this differ from the ones I get from my extremely competent expert suspension guy for all my other cars? That is, isn't the car always at "ride height" if he just drives it up on to his rack and works his magic? Frankly, MB dealers charge 3-4 times normal for this service, and most dealers don't have the same grade equipment as my specialist has at his disposal (at one of the Detroit Three's hi-po test garages, highly calibrated)* or the same degree of expertise with someone who does them all the time and slowly, not speeding through for the economics of gaining against the book time payment.
Can't I just get my usual guy to do it next time when I'm ready later this year? If it was a steel-sprung ML, I would not even ask. With Airmatic or whatever -matic MB now calls it, I start to wonder if the dealer procedure requires sending some computer commands via the proprietary diagnostic machines to somehow properly set the car up for the alignment. For their quoted pricing, maybe they bring Elvis Presley back from his grave to croon to the cars while the tech tickles the toe settings. . .
*When I got my new Miata this month, that franchised dealer declined to check the alignment per my request stating that his rack was ancient and not as good as I'd find elsewhere given that I'm the type to check even a newly built car's settings.


