NAAA uses evaluations based on actual recent transactions, as I
understand it. When I was looking (6 short months ago), I concluded
that NAAA was based on more accurate data. When you get around to
actually making an offer on an aircraft, I suggest hiring a NAAA
appraiser to actually do an appraisal. Their reports can come in handy
as a bargaining tool.

-Sami
N2057M, Piper Turbo Arrow III

GE wrote:

I'm a new pilot looking for my first bird. I'm mostly looking at TAP,
Controller, and ASO. Whenever I find a plane that meets my needs, I am
finding a huge disparity in the values returned by AOPA's Vref and TAP's
NAAA evaluator. I have read in this newsgroup that Vref runs about 10% high,
but I'm finding a much greater difference than that. Any advice for someone
who is new to the game? Are there other places to evaluate aircraft online?