There are some great suggestions here on down payment, interest rate, servicing, and underwriting the borrower.  

Like you said, I do believe you'll see more firms with "all services under one roof" moving forward. 

This is a FREE service provided by the bank, and we have used this account for about 15 years or so. 

Landlords mistakenly ASSUME all PMCs offer the exact same services and operate the exact same way, so price is the only differentiator.So, the first question they usually ask a PMC is about fees - instead of asking about services.This also leads them to ASSUME simpler is better when it comes to management contracts.

Owners mistakenly ASSUME all PMCs offer the exact SAME SERVICES and PERFORM those services EXACTLY THE SAME WAY, so price is the only differentiator – so, they often select the first PMC they call or that calls them back!

This is not only my experience, but when you call VRBO or Airbnb customer service, they will tell you the same thing.  

Lenders usually determine whether properties are lendable based on the debt service coverage ratio. 

Customer service from a support perspective matters of course, but no hang up or delays on investing would take place.

Could be the tenant is not using the service, doing something to attract roaches or the exterminator isn't doing their job.

Look into a DSCR, Debt Service Coverage Ratio, loan where the rental income can be used to qualify the cash out refinance instead of your personal income.To Your Success!