If you know the area, you can generally estimate with accuracy what the rental income should be.

I tend to like the accuracy of Redfin within my market.

Conversely, the higher the Preferred Return the less important the accuracy of the comps or projected sales price.

Clearly the pitfalls here are time and accuracy.  

It had accuracy within a couple inches and could navigate the rows it planted.

(Clear as mud...I know).The accuracy comes from the statement "you should build a business first".  

Yup, but not with guaranteed accuracy. 

We do a good job of compiling voluntary liens (mortgages), but we don't currently track involuntary liens (IRS, judgements, etc), and since our systems build title history on tens of millions of properties, no human has verified their accuracy, and we certainly do not guarantee it. 

My criteria are speed of work and accuracy of estimate.

you can have the tenant provide the form already filled out and you just need to verify accuracy, and sign it. unless they paid rent in cash, then you needed to provide them with receipts, if you are in TX, do you have a manager collecting for you anyway?