I have a spreadsheet that runs the numbers on what the seller is asking along with the ability to run scenario numbers to hit sample benchmarks. 

Given your thinking about buy and hold, I am also not sure that I would look at ROI as my benchmark.  

Two questions: 1) is there a sound resource you recommend for the daily benchmark rate these numbers refer to?

Finally should I hold my current properties until they reach a certain bench mark?

Michael Gomez with Benchmark is an investor / broker and runs a Huge BP meetup along with podcast guest Seth Mosley.

When I transitioned to RE my returns doubled and I was getting consistent pay checks month in and month out.When you compare RE to stock returns I feel as if so many just look at the S&P and use that as the immediate benchmark for what they would have had as a return.

Thus, if she wants to buy me out or decide the sell the property we have a fair benchmark with which to evaluate my interest.

I'm trying to get my rental analyses fairly accurate and was wondering if the 50% rule is a good benchmark in Suffolk.

That's my benchmark anyway. 

There are so many variables not taken into consideration aside from   location and square footage that its is only of use to the county for setting a bench mark to collect taxes.