Long story short, we frequent Boston a lot.

We frequently get asked if we accept vouchers but we don't.

I know we have several CPAs frequenting this forum. 

We close a frequent number for our clients and they seem to worry about this the most.

Such a poor-performing property manager will result in more frequent tenant turns, more frequent maintenance, which generates more income for the property manager.Another claimed advantage is that there is already a tenant in place.

Also any recommendations on how to avoid these frequent repairs?

Know your climate, so how frequently are you going to need to turn any heat source on?

For future reference, while appraisals don't always come in below intended purchase price, you can expect this to happen more frequently given today's market. 

@Joshua SunI am a CPA and I have frequent conversations with real estate investors to become potential clients.I find it that the conversations are not great when the 'investor' is very early on in his real estate journey(doesn't know a market, doesn't know what or where he will purchase his property).I find my conversations much better if the investor is at least under contract or has a good understanding of what he wants to buy.

One source of cities to avoid is Neighborhood Scout's 100 most dangerous cities.Disaster Risk - Some parts of the country suffer frequent natural disasters.