I would not say that this is extremely dangerous for foreigners but can really affect your life or business. 

You have gotten some great feedback here already, but since you mentioned the property is already listed, it changes some things.Reviews are definitely extremely important to the success of your STR.

They are not even programmed to do far simpler sniffing tasks than this, and a year-to-year comparison is extremely hard to automate, both technically and logically.Who does it, then?

-It was extremely difficult to work with but I would do it again.5.

It's extremely different from 10 years ago. 

One is going really well and the other has been extremely frustrating.

There are companies spending $100k a month on mail and all the smaller sized companies / people all get their data from same sources (like Propstream).To me it didn’t make sense to use the same info as it is extremely difficult to have any type of advantage

Their reports are more expensive so you'll only want to use it on a house where you are sure there is a deal to be had, but the report was extremely detailed and allowed me to find a very transient owner.Just my 2 cents worth, still interested on the opinions of others on this topic.

What makes you think you can do it right now with high cost of money and extremely low inventory along with a glut of competition who knows more than you?

I've received different advice - on one extreme is sell off all your rentals, take the cash and take the capital gains tax hit and invest in stocks/index funds (not from a RE investor, from people I know who are horrified that I have more than one mortgage), which I won't do.