Greg.
Cowling off to cowling on, inspection has taken me 21-22 hours. This includes the routine oil and filter change, oil strainer, fuel filter, fuel strainer, air filter, wheel bearings, etc.
I've advertised my RV for sale and a prospective buyer had a well known person from the Atlanta area do a pre-buy inspection. I removed the cowling, front wheel pants, baggage bulkhead, tail fairing, inspection covers under the aileron push tubes. He and son looked over everything in about an hour and a half. Yep, 3 man-hours. They found every deficient thing I knew about and several things that were a surprise. I looked over their printed checklist. Everything that is on my inspection checklist less some items. The did a compression check. They did not pull strainers, filters, seat pans, repack wheel bearings or change the oil. They did not clean, lubricate, grease, adjust, tweak, fiddle or talk. They knew what they were inspecting and looked hard. They were a lot more efficient than most of us with their inspection.