I live in a heavily real-estate depressed area of Florida, and I can tell you that at least around here, Zillow is just flat out wrong. Well, they are getting closer to the right answer, but there has been a tremendous lag, at least 18 months. Not sure that Zillows method can be considered the Rosetta Stone of Real estate pricing.
Zillow is to appraising what Roni Deutch is to tax consulting.