If so, what are the advantages of buying real estate to stocks with IRAs?

I treat our Denver and Colorado Springs investments like stocks.

Originally had an order in for 3x 8' culverts that would be roughly $547 each because no one had them in stock.

You can buy a stock, in lets say apple or Microsoft, but that doesn't give you a seat at the table of CEO, CFO, COO ect... but In syndications, you can talk with the managing partner and get all the information, strategy, and experience ect.... 

Should I save and pay it off quickly or would the money be better in my pocket or in stock market? 

I have about $500k in stocks and about $600k in equity in my single family house that I rent out.

Whether real estate, stock dividends, bond yields.

It’s good to screen tenants with all the standard checks, however I put the most stock in rental history.  

This larger downpayment would require me to liquidate stocks which I am not too keen of doing at the moment.As an active listener of the BiggerPockets podcast, I'm well aware that midwest markets like Indianapolis, Cleveland, etc. are the "top" markets these days in terms of current growth + affordability.

It's more like directly investing in non-Fortune 5000 (yes, that's 5000, not 500) stocks.- What do you think will happen if you do this without a LOT of research?