Property managers generally do a decent job handling the paperwork involved in managing STRs for owners. HOWEVER,
Property managers need to have well-established, trained, capable and competent cleaning teams who will properly conduct the turnover cleanings between guests. This is a significant area for failure IMO.
When I used a property manager they would block out days as "could not rent" on my calendar due to limited cleaning staff. I did not expect same day turnovers between guests, but blocking 3-5 days on the calendar because they could not get a cleaner was poor planning on their part.
They also did not check on the work done by their cleaning staff which led to complaints from guests as to the quality of the cleaning and the refresh of necessary supplies (toilet paper, etc.).
Exterior yard work was not done. Hot tubs were not cared for. Stained linens were not removed or replaced, and necessary cleaning products were not made available to their staff. There was little to no oversight.
Good luck with your venture as a property manager -- just remember that you are only as good as the staff that you have hired for the maintenance and cleaning.