I don't disagree with you. I was speaking solely about full mortgage -- ie, minimum down payment. Turning a positive cash flow with a large mortgage is very difficult, especially after accounting for all costs. (Mortgage, taxes, insurance, maintenance, hoa, vacancy...) Turning a positive cash flow without any mortgage is very easy, but kills your ROI. So you're going to end up shooting somewhere in the middle...

EDIT: Here's a fun Reddit thread on the topic:

https://www.reddit.com/r/RealEstate/comments/36ikp6/landlord...

Here's an example from that thread on how quickly the math takes you to roughly cash-flow neutral -- and this is with 25% down and 1% rental price:

https://www.reddit.com/r/RealEstate/comments/36ikp6/landlord...