Another option is to consider strategies other than LTR that may increase the gross revenue like renting a unit or two by the room to college students or perhaps testing a corporate furnished rental concept.

I just briefly looking up the Smith Maneuver, a fascinating concept, any downfalls?

I'll let actual investors speak to your questions from real life experience, but wanted to help you approach the concept from the right starting point.  

It was his stuff where I first seen the concept that a house (buy and hold) has all kinds of ways to make money from tax benefits, to appreciation, to equity build up as the tenant pays it off and of course cash flow.

If you mix the two concepts, it can monkey with your cashflow pretty badly.

It doesn't mean I ever UNDERSTOOD math concepts though.  

It may be because this is a mainstreaming industry with some ever-changing and new concepts.

This is a concept I heard in a BP favorite, Rich Dad Poor Dad - whenever you want a depreciating asset, buy an appreciating asset to pay for it.Let me know if you're in the Chattanooga area or have similar RE goals! 

If you haven't read Rich Dad Poor Dad this will clear this concept up.

Most of the cases I saw involved institutions buying whole neighborhoods, not scattered individual houses, so the concept was similar to my original post.