Since we're talking about 'opinions' - in my opinion you don't appear to have sufficient understanding of altimetry to make valid statements on this thread, Hopharrigan. Do you know the difference between temperature compensation and temperature error correction?? Perhaps you should go and have another look at your theory book before pestering Boeing with your queries?? You do have a theory book, don't you?? Or did you just do the FAA tick test for your licence??