How do you see the Diamond through Rough

[John O.]

I'm a numbers guy.  I look at a house and I see its numbers, specifically cash flow. However, I recently did a deal that bit me a little bit.  Honestly, I was so focused on the numbers and projections that I neglected to look at the problem staring me in the face (see my post in another form about this deal here. Essentially, I looked at the trees and never saw the forest.

There is this soft side to evaluating a property that I am actually unclear on. Perhaps this is where the art in our craft comes into play, but my question is this:

When you are looking at a property in which the numbers appear to work, what criteria are you using to evaluate the non-quantifiable aspects of a potential rental property?

For example, how do you evaluate the floor plan? The finishes? The feel of a property? What are you looking for?  What do you avoid? How do you know there is a diamond behind all that foreclosure rough?