Update: I quit using the county tax assessor's site for comps and started walking the cul-de-sacs instead
For 4 years in Alpharetta I pulled comps straight off the county site because it was fast, but after 3 neighbors told me my "renovated" comps had unpermitted additions, I started driving the actual streets on Saturday mornings. Last month that 15 minute loop saved me from pricing against a house on Windward that added 400 sq ft with no permit on file. Does anybody else do drive-by checks before listing, or do you trust the county data?
Have you ever checked the permit history before you even leave your car? I pull up the county site on my phone right there in front of the house and compare what I see to what's on file, because that gap tells you everything. Walking the street beats stale data every time, and the neighbors will usually tell you stuff the records never will.