Jafar, do you mean that a store-bought local apple variety has a lower brix than the same apple variety  that was ranked - for example a locally-purchased King David compared to a ranked King David?  Or do you mean, just in general?  How do you think that either brix level would compare to home-grown apples that are left on the tree until fully ripened?  One of the most curious realizations in growing my own apples is how variable the quality has been, from year to year.  For example Liberty apples have ranged from excellent to decent, from the same tree.  I wonder if brix levels would correlate with this.

Brush, that's a good question about Brushy Mountain Limbertwig and something that I've wondered also. I had always heard, growing up only a few miles from where Golden Delicious was discovered, that it should never be grown west of the Mississippi River; that doesn't seem to be true, though.  So maybe it's worth a try, and maybe there will be scions at the HOS Fruit Propagation Fair in March.