When you see a watch at an AD, it never shows the true AR on the crystal, due to the lighting etc.... If you were to take a gen and a rep into normal daylight conditions and wear both for a day, the difference would be very obvious.
For example, I wore a UPO the other day and had a look from the outside of an AD a the 45mm gen in the window, and the AR looks very similar. However, when I wear my Breitling Aerospace (which has a similar AR coat to a gen PO) and compare it to the AR on the UPO, there is no comparison.