A good appraiser will not just average the comps, they may do a weighted average or base their final opinion more heavily toward a more similar comp, but more than one good comp is always preferable.Now with that said, as a longtime appraiser/broker/investor, I have seen some pretty "questionable" appraisals, so it can be a shot in the dark sometimes - unfortunately.

I'm from Dallas, and I'm not sure I agree with @Joseph Cacciapaglia that Dallas is not that diversified or too heavily reliant on the finance industry.  

You can look up data in specific neighborhoods regarding household income, crime rate, and % owner occupied vs renter homes, but the growth that Columbus is seeing means the data is still heavily transient, so subjectivity with some insight as to how businesses and neighborhoods are currently developing is required, which is something that I would judge based on aggregate responses from multiple real estate agents (along with my own experience as well of course).

Im heavily invested in churchill downs and looking to expand south as well.

If you're investing in a heavily tenant-leaning state (NY, MA, CA, etc), it might not be as wise.

The Agency’s investigations are complaint driven, so we rely heavily on the public, and our licensees to bring these individuals to our attention.

On my long drive from Kansas City to Texas, I happened to listen to a TED talk on the subject of investment in Africa, in which the speaker alluded heavily to the real estate potential in South Africa.

He was/is heavily invested socially, culturally, and economically in the area.

Weigh heavily the experience of the people you are talking to and their motive to help you before working with them. 

Vendor docs electronicallyI rely on iCloud and iScanner heavily.