My last two experiences were such that I will definitely be changing my oil until I'm too old and decrepit to get on the garage floor.
Most recent experience was a Ford Quick Lane and my sister-in-law's Ecoboost Mustang this past summer. I requested the bump up to Mobil 1. Drove the car to a local coin-op car wash afterward, and after spending about 30-40 minutes drying, vacuuming, and dusting, found that the oil level was below "add" on the dipstick. Called them to advise that I would be dropping back by for a top-up.
While I and 3 technicians pulled, re-pulled, and re-pulled the dipstick in the Quick Lane parking lot, the tech that performed the oil changed exclaimed " I added 6 whole quarts of Mobil 1 5W-20". I requested that they change the oil again, as the oil cap, owner's manual, and their computer, all say 5W-30 for this engine. 10 minutes later, they claimed to be done. I don't think they did anything except top it up.
Prior to that, I took my brand-new 2000 Nissan Sentra to Jiffy Lube for it's first oil change. I drove away, and as I approached the first stop light, smoked oozed out all around the hood, and the stink was unbearable. I pulled over and found that oil was dripping directly onto the exhaust pipe directly under the engine. Back it went. They got back underneath, did nothing, and gave the car back to me, claiming that my block must be cracked. I drove the smoking SOB home, got underneath, and installed a(nother) new oil filter, and tightened it by hand, and then an additional 1/4 turn with a wrench. Added about 1/2 quart of oil and cranked it. No more leaking or smoke.
These two are my previous 2 experiences with having someone change my oil for me. It won't happen again.