in his pro forma he shows this property at a 20.87% cash on cash return based on his assumptions; however, when I run mine I'm getting 7.91%.  

It provides an intuitive interface and a powerful calculation engine, which would be very costly for us to duplicate.But to make a tool that is both powerful and usable means we have to do a lot more that is not visible to the user as part of the familiar Excel skin.

We run a professional business.  

That way you don't run the risk of shrinking your buyer pool, because in the end, every little extra add on money-wise is a deterrent to the end buyer. 

FYI: I also run three of the largest real estate investor groups on LinkedIn with over 20,000 combined members.  

Of course, I would have to run the numbers on any property.

Speak with a couple of local agents and ask them to run some comps for you.

I'm financing a deal and the ROI 10% but I feel if I wait for the market to collapse I would get a higher return and won't run into negative equity.

Make sure you run the numbers if you decide to use the equity in your primary on an investment property.

The area and houses around just looks more run down and cheap.