gen Planet Ocean has the best AR I have ever seen on a watch. Omega also updated the coatings midstream so some older Planet Oceans have a bit more of a blue tint. The new ones have a barely any hue, maybe a bit smokey in color.
On 5th gen the ar is better than the 4 gen, close but not close enough... With the sun hitting the gen crystal and the gen dial under you will see what i am talking about lol... Lets say 7.5-8/10 comparing to the gen one if that helps you...