I just finished my equipment specialty at my LDS and I had a blast. everyone got a turn to disassemble and re-assemble some of the shops worn out gear and we reviewed cleaning procedures and in field repairs, but we didn't actually do any of the cleaning. At the end of the course, everyone was expected to be able to balance their reg and set the intermediate pressure.
At the end of the course my instructor told us "what you have just done is exactly what I do when I am servicing a reg. the only difference is that I do this 4 or 5 times a week where as you would do it once every year." And his point is valid. You could do your own services if you wanted, but someone who work on the regs regularly is less likely to forget a step then someone who does it yearly.
I took the course for field repairs. I found the thought of calling a day of diving becasue an oring blew that would take 5 minutes to fix if I only knew how, unpleasant.
If you decide to tak the couse, check with the instructor to see what kind of hands on training you can expect. That will make or break the course.