Good companies have problems. 

I was an investor first but now manage a property management company in central CT.  

For years I put in all my contracts that a specific appraisal company could not be used for the appraisal of any deal I was doing because their results were consistently so low it was laughable.

If you want to PM me the address and info I can give you more specific opinions on the property and what this turnkey company is telling you about rents.

After giving this vendor a $15k deposit I started to get some weird vibes about them and called the utility company.

I know there are some negative reviews of his company from a couple years ago.

You have $1.5+ million home and you're paying $2000 property tax a year, probably a paid off mortgage  if you bought in 1970 for example, and can charge market rate rent (multi units are under rent control with existing tenants, generally speaking, but not SFHs so far) Be really careful with whoever gives you numbers on a spreadsheet whether it's a turnkey company, agent etc. 

@Justin StearnsEncourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

From there, I'd recommend reaching out to some of the smaller property management companies in your area.

I'm working for a family run real estate investment company and we're new to the DFW area.