The problem with most appraisers is not that they are using the latest greatest sale prices, it is that they only think they are using them. By the time they get done injecting their personal out of thin-air adjustments for intangible/subjective features such as condition, quality, view, functional utility and so on, they have effectively altered the sale price of the comparables. They frigging don't know what they are doing -- most of them [OK, my guess, as I have only ever seen a very small fraction of other appraisals in existence.]
Your statement most appraisers don't know what they are doing is flat out wrong. Esp considering the scrutiny appraisals receive.
The SOW effectively alters the sale price of the comparable ( with applied adjustments ) that is the point of an appraisal -to find the equivalence between prices and market value -and market value is supposed to account for physical and locational differences between properties.
With all due respect, some of your comments about appraising sound like they come from planet MARS...
When I say "appraisers" I mean reviewers as well. Everyone else except me - as far as I know.
1. So. for example, let's start with GLA. Maybe the true price per square foot adjustment is $200/sf for the range of comparables we are dealing with, according to the best possible regression. If the appraiser adjusts, for the sake of argument at $400/sf and most of his comps have less GLA than the subject, then the adjusted sale prices for homes will a lower GLA than the subject will be higher than they should be, just as if they had a higher sale price than they in fact do. So, given his comps are unbalanced, the resulting value estimate will be too high if based on the average adjusted sale price. -- The opposite is true for homes that have a higher GLA than the subject. So, by using that large GLA adjustment, you force the sale prices of some comps to be effectively higher and other comps to be lower. You should be clear on that with a little thinking. And that is one reason evenly balanced bracketing is desired - because it will tend to negate the impact of improper adjustments. Unfortunately you usually cannot balance your comps in all respects; especially if the subject is at the extreme end of a range. But of course, note that a good appraiser can likely nail another appraiser who does a poor job in selecting an adjustment for objectively measured GLA. So, this example, is used just to make clear how this sort of thing works.
2. Now, jump to the intangible/subjective type adjustments such as for Condition, Quality, View, Functional Utility and so on. The problem with these kinds of adjustments, is that it is difficult for a reviewer (who doesn't know what he is doing like most don't) to decide whether these adjustments are too large or too small. Correct me if I am wrong by telling me just how you would be able to determine this. My guess is you don't really have a clue. ... Because this requires a deeper understanding of the Sales Grid than you will find in ANY book on appraisal.
No, you are categorically wrong. But, then you. just like thousands of other appraisers. wouldn't know any better. You don't even have the faintest clue.
You need both advanced tools and advanced understanding to get around these problems, - and in complex neighborhoods that can be a real chore.