Last night our club had our first open-to-the-public observing sessions in over a year and I brought the 80mm Aplanat. Low power views were excellent: Pleiades, Alberio, Andromeda and especially the double cluster. When I tried to up the magnification on Jupiter and Saturn the views got mushy. Unfortunately no other refractors of similar size for comparison.
I always thought that in terms of performance and color correction the Aplanat should be in between the original achromatic Nighthawk and the 80 ED.
The Aplanat is an achromat. An aplanatic lens is one that is free of coma and spherical aberration.
As such, the chromatic aberration will be slightly better than the 80mm F/6 Achromat. The Orion ED-80 is in a different league.
One way to characterize a refractor's color correction is the compare the diameter of the chromatic blur to the diameter of the Airy disk:
80 mm F/6 achromat: Chromatic blur = 5.2 x the Airy disk
80 mm F/7 achromat: Chromatic blur = 4.4 x the Airy disk
ED-80 Orion F/7.5 FPL-53 doublet: Chromatic blur = 0.71 x the Airy disk.
The ED-80s chromatic blur is smaller than the Airy disk, essentially free of chromatic aberration.