Revisiting the p.15 scale drawing of the Enterprise-D, Defiant 74656 and DS9 together, I can certainly believe that each pylon "rises" or "falls" 126 decks in each "direction". I wonder what the view from inside Ops would have been of the upper pylons.
Yes, 969.26 meters (p.16) divided by 252 levels yields 3.85 meters per level, a fairly typical Rick Sternbach deck height. On the other hand, Doug Drexler was making his cross-section look good by visually matching the Core spacing which became much higher than expected due to the upscaling, so his own extrapolation suggests a much lower number of levels, especially since they seem to be double-height in places. (Drexler posted a digital version of the diagram at ArtStation.)