Rick H. mentioned, reliance on calculators hinders your ability to think instinctively , objectively, you won't be able to adapt variables in reality that come to play in the analysis of real estate, or law, or economics, or finance or accounting or any other professional endeavor that requires intuition, abstract thinking or layers of relevance of variables in circumstances or situations. 

Quote from @Sam Yin:  To top it all off, it will begin to erode reliance on MLS and can begin to take us back to the old days of real estate, prior to the Internet. 

Unless the seller of rental property has depreciated the place to the point where is no longer severs their needs or there is another good reason to dump the place, reliance on their numbers is not a good idea, Chances are it was mismanaged.

As you stair step more portfolio properties you can decrease your reliance on your job as a large source of income.

I see them both coexisting and reliance on real estate agents going down but very slowly.I already see in my market some wholesalers and other sellers listing properties on Zillow and getting lots of leads.

Stating the property will be used for Primary Residence and that the loan is in reliance upon the continued occupancy status as represented.

In CMBS: due diligence is the foundation of the process because of the reliance securities investors must place on the specific expertise of the professionals involved in the transaction.Engineering Report: Report generated by an architect or engineer describing the current physical condition of the property and its major building systems (i.e., HVAC, parking lot, roof, etc.).

As Rich Dad Poor Dad indicates the knowledge is priceless and there is no way investing OOS with a PM you obtain the same type of knowledge 2) requires less reliance and trust on others.

when I first started researching investing in syndications, one of the first web pages I found was this:http://www.nasaa.org/22284/informed-investor-alert-private-placement-offerings/ Private Placements and the Risk of FraudEntities raising capital through private placements often have a limited operating history and typically have more modest revenue streams than larger companies.Because private placement offerings made in reliance on Rule 506 of Regulation D are not reviewed by regulators, they have become a haven for fraud.According to the most recent enforcement statistics from the North American Securities Administrators Association, private placement offerings are the most frequent source of enforcement cases conducted by state securities regulators.

I definitely need to break out of a reliance on sites like Zillow before I get burned.