I like your stock analogy with some diversification in your portfolio that offsets one another.

Multifamilies in Miami Beach are very expensive and usually purchased by foreign investors for wealth preservation and diversification purposes, and sell for very low cap rates. 

That's called diversification and a sound financial strategy.

I like how I'm not going it with more than $25-50k at a time for diversification sake. 

Depending on how much money you have to invest, start diversifying into other strategies and asset classes  to both increase your return and give you more diversification protection.Blackstone has an excellent Core plus Fund, although it does require a little bit more net worth than typical. .  

I'm an advocate in diversification.

That may or may not matter to you - some people just like to hold real estate because of diversification, or they feel it's safer, or they are counting on long-term appreciation, or it makes them feel like a big shot.

The diversification has allowed Texans to not only survive but thrive.

To me the important ones are appreciation, then principle pay down, then depreciation, stability/diversification and then cashflow.

Through proper diversification your $50K SDIRA could return a double digit return with not much risk allowing you to focus on other areas of real estate.