Scuba pro does not want individuals servicing their own regs, only tecs working at SP dealers, HOG is more in DIY friendly in this regard. The company is more appealing to me for this reason and may be to others as well. That is my only point.
Probably this changed over time.
I was trained at the Italian Scubapro factory, and not only the technician did show me how to service my reg. I was sent to the assembling line and for approximately one hour I replaced one of the workers, mounting and tuning production regs (just two, in one hour).
I was yet an university student, not working for a shop.
It was a real "hands on" training, with little theory, apart when they did show me the machine for measuring the cracking pressure and the other one for charting the respiratory cycle.
I had understood that all the technicians allowed to service SP regs had the same training.
It must be said that, in such old times, there were no "diving shops", nor "diving centers".
Teaching was done only at diving clubs, which was the way I managed to be trained. There was no PADI, nor other commercial training agencies.
Good clubs, with hundredths of associates, were allowed to make "bulk purchases" of diving equipment directly from the factory, usually once per year, and SP wanted that at least one instructor was properly trained for servicing their regs in each of these clubs.
Most divers did own a boat or a Zodiac, perhaps sharing the costs among 2 or 3 friends. There were no divemasters, diving was always a self-guided experience.
After having being trained, I was responsible of maintaining the huge set of cylinders and regulators of my club (and the 5 surviving AROs, pure-oxygen rebreathers).
I know that all this looks strange for people in the US, where diving (as almost anything else) has always been mostly a commercial activity, not a sport practised under the national Olympic no-profit organization.