I left with a sniffle, with bleeding fingers, cracked lips, and a perpetual risk of a nosebleed in the heart of Denver winters that get so cold, my toes start to turn blue after 5 minutes outside. 

It kinda just slipped through the crack.

--reach out and thank them upon getting the booking and ask if they have any questions--send a "Welcome" email or automated message during the week prior to arrival--reach out the day after arrival to ask how everything was the first night and ask if there is anything that the property needs--reach out at the end of the stay (that morning or within 24 hours) and ask how everything was, anything to improve, anything to add to the house and then offer an incentive for returning guests.My 2 cents,Mike Absolutely stay in your place as Mike said.You will see things the cleaners will never let you know about.We stayed in our PF will putting up the Christmas decorations and found a cracked plastic shelf in the fridge. 

Kitchen cabinet handles were placed upside down, cabinet doors were installed backwards, electrical line for thermostat was ran on the inside of the bedroom exposed, trash swept into newly installs vents from the furnace, cracked tub, wall switches were installed sideways in some rooms, wall outlets were installed upside down on some walls, list goes on.

From the top of my head - mildew, moisture buildup, dust, structural cracks...

You mean the water was so heavy that it cracked the floor joists and the entire floor and basement ceiling fell in?

monthly emails crack me up.

Check for cracks in the foundation, condition of the mechanicals, any water coming into the basement, etc. 

But without pulling out rotten drains in tiny bathrooms and listening to people in need?

If it is the same, there may be a tiny, marginal benefit* that is not worth the extra confusion.