There's a lot of variation in values within pockets of Milwaukee.

All systems (Mac, Linux, x variations of Windows) are exposed.

How much of a variation you want on that is up to you.

The PV format does not allow for such input variations at all.  

In the excel file, I can just copy and paste column B from the Deal Evaluation tab into column C, D, etc... to create as many different financing variations as I want and compare all the numbers (cap rate, CoC, etc) for each variation right in one view, something that is impossible using the online tool.Also BP only lets you make 4 or 5 reports if you're not a pro member, and you can't print them if you're not pro.Also using the site means you have to have a solid internet connection.In case it wasn't clear, there are 3 tabs in the spreadsheet, "Deal Evaluation", "Closing Costs", and "Capital Expenditures".

@Cody May,Slight variation on Thomas S.'

I am a software engineer by undergrad degree and trade and i've got a JD hanging on my wall that I don't use for much more than experiments in how temperature variations effect dust collection rates. 

So variations here could be much worse than illustrated here.When we look at the combined investments in reality you do not "make" any money from the loan investment.  100% of those payments are being allocated to pay down the mortgage.  

Your mortgage will then only be principle and interest.With this, you monitor the Tax assessor for appraised value and rate changes.We're luck in Calif as Prop-13 mandates the assessed value to be 1% of purchase price (fixed) so the variations are in the rate changes.For marginal cash flowing rentals, changes in appraised value or tax rates can be a killer.

But if you try enough variations, you'll find it.And I'll leave you with one other advise.