Its a very powerful strategy and you will build more wealth using that strategy long term than investing through a SD-IRA. 

These neighborhoods tend to have zero appreciation at best and at worst negative appreciation after accounting for inflation, and you still don't control that but you sure as heck should care because you are then loosing purchasing power every year.

So its just not one size fits all. its regionalized and frankly if these folks starting out think they are going to  be investors when they really have no money ... and no skills.. then well like you said 95% will never do a thing.. while most should concentrate of getting out of debt and increasing their earning power.you don't get wealthy or a lot of earning power in the leverage rental houses game if you do not have a lot of liquidity going in.. and or can attract investors to help you or other strategic partnerships.And like you said you been doing it 15 years.  

I may make a mistake in repeating it, but from one of the podcasts.If you have a bunch of power tools in your garage and you go away on vacation for a week.Class A neighborhood:  You leave the door open, your neighbor calls you two days after you left for vacation they saw the garage door open and shut it for you. 

@Andrew Johnson thanks for the input - I understand the logic of being on every list and then going with the one that is lowest but that simply isn't the most efficient use of my time.

Tenant Cloud probably leads the industry in regards to power of accounting features. 

Once upon a time there was a borrower who took ill and gave his daughter power of attorney.

PM is a nickel dime business and if you aren't incredibly efficient you will be out of business quickly.

That said, they're more expensive, have fewer buyers (though the market around here has been very active for that property class), so if you decide being a landlord isn't for you you may face a longer time to sell.Also, with larger properties you get into efficiencies of scale, where by having more tenants, maintenance issues, etc, centrally located, you're able to deal with those problems with less travel time and operating costs because you/your handyman can do multiple repairs without having to drive between multiple properties. 

However, possible real world positive implications would be using your wife's name/income to qualify for some of your mortgages increasing the number you can have, or boost your buying power on a mortgage you both cosign.