Well you see, NOBODY can do as good of a job on MY equipment as I can. It seems like most repairs come down to diagnosis/ remove & replace. Even if it is working on something where I have no experience, I can learn and address other things along the way. A mechanic might know exactly which bolts to remove to get to a certain part, but I might have to thoroughly clean the entire area to figure it out. Then I would check ALL nuts and bolts, usually finding a couple loose ones. I will also stop to reroute/tape rubbing or worn wiring, which a mechanic wouldn't mess with.
It might take me twice as long, but I usually feel better about the equipment afterwards.