The curated model is only as good as the people curating the deals.  

My feeling is that if a finance whiz did a mathematical model on these approaches you would come out ahead focusing on one specific property at a time for early paydown but I am not that whiz so I won't undertake to prove it with math.  

What are your goals and what does each business model have for your style of investing?

If it's based mostly on pricing models, inflation and national trend charts, then possibly.

I personally built around a 10-12% cap rate, $150/door model with purchase at or close to 80% ARV when completed.

Discovering BP has played an integral role in providing me with valuable resources to make decisions and creating a business model.  

The IRA LLC model has been around for more than 20 years and has been tested in the courts.  

You want a flat fee / fee for service model, not a model that is based on the asset value.If you qualify for the Solo 401k and would have other reasons to take advantage of such a plan like the desire to make higher contributions or other investments, then it might make sense to explore that platform.You don't need the checkbook control of the IRA LLC or a SoloK for a single land asset.  

A "Supply-side" economics model, in a way.  

The benefit of using an open input model like excel is that you can adjust prepayment levels of the loan which if the loan is purchased at a discount will have a direct impact on your IRR.