They are very different. 

I've spent a great deal of time speaking with many investors in different markets ranging from state to state (but not in my own in TX) about voucher tenants.

This Wikipedia page gives different wall types and how well they block sound.  

Legal Entity Considerations: Should I hold my rental properties in an LLC or trust for liability and tax benefits, or does it not make a difference for me?

Check out the different Forum Categories here as they can answer a lot of questions you have just reading through.

Then look at different REI to scale to that number.  

Steps: you go under contact with the owner of the property, you assign the purchase and sale agreement to the end buyer, the end buyer closes, and you get paid the difference between the agreed-upon price between you and the owner and the intended purchase price of the end buyer. 

You are correct; it would be awkward having two different parties staying on the property. 

It might be payment notices are going to a different address and it is simply overlooked. 

Waivo has a different but similar product they sell directly for STR.