I'd love some insight into what it is you're seeing as an investor that leads you to that conclusion.  

Have a plumber do an assessment and get their conclusion in writing as evidence that you did your part as a landlord.

We sent about 1000 letters and we hand wrote a lot of them.We had 2 responses.I came to the conclusion unless you're doing the things @Marty Boardman recommended or more you're wasting your time.

Should I get my own realtor to evaluate and see if the conclusion is the same?

You are MARKETING for foreclosures, (so you are going to get ONLY foreclosures) and if it takes you 100 foreclosure leads to get 1 deal.. that is 1%... so conclusion... foreclosures are NOT motivated.

Now, before anyone jumps to conclusions, no it didn't drain under the house.

You do need both to make a good decision but data can be confirmed whereas you need multiple opinions and then come to your own conclusion when it comes to opinions. 

How did YOU JUMP to that conclusion? 

At the conclusion of the league's season, I won the trophy for "High Score Handicap".

Different period of time different results, no surprise there.And thirdly, other factors such as taxation and inflation are throw into their equation.And fourthly, there conclusion focus is taxable products versus non-taxable products not a comparison of real estate to stocks.Different time period, different focus, different factors = different conclusion.