Mike, congrats on the APOD.
The galaxy's outer reaches show up amazingly - as almost never seen, and the clarity of detail in the main spiral is spectacular.
On the matter of resolution, I'm sure you are right. I recently changed from 1"/px to 0.65"/px, and it shows at my Mt Macedon site which never gets much better than 1.7" seeing...
I'm very jealous of you getting so many hours of sky time - recently I've been lucky if I can two decent nights with good seeing in one dark period
Mark