The property tax savings are going to be in the ball park of 40-60%, but to be safe you should double your expected repairs budget when calculating the NOI.If you have any other questions, or want a more in-depth response, I would love to help!

So the question becomes based on their individual and personal tax situation what is the estimated tax burden they'd save? 

Taxes, costs, eviction complexity, etc are going to be a much bigger factor in your success than anything else.

From a tax perspective, you'll want to take what you paid for the property plus calculate the improvements you made to the property during your time of ownership.

If a single-family owner-occupied property is worth $400,000 - I wouldn't invest more than $280,000 (70%) in a note secured by the property.ITV takes priority over desired yield - so even if the note discounts to $350,000 based on desired yield, the investor still won't go beyond their maximum ITV. 

STR seems to have better tax benefits (in the right market) but is it worth it at a distance ???

Tax Breaks- I am not an accountant, but I recommend conversing with one to see all of the benefits to owning a rental property.

I would check this out with a seasoned securities attorney for their opinion/guidance.  

Tax-Free Exchanges: While 1031 exchanges aren't available to SDIRAs, the tax deferral within the account means you can sell property and reinvest proceeds into new opportunities without immediate tax consequences.

At least now your tax basis is $220k ;-)  What was the extent of the repairs?