Straffo,
I'm sure the D.520 would be a great early-war plane.
Thing is we need a Rolling Plane Set, or the vast majority of those AC are worthless..except scenarios.
I really am terrified there never will be one in AH..this "Perk Plane" business seems to be in as a substitute. I worry there's a fear of copying WB too much (err, re-doing it, since it was Pyro and HT who started the RPS over there) and too much of a desire to be different just to be different.
I realize the RPS has been insanely controversial over in WB, but I really loved it (back when I was in WB). The problem is, to make an RPS work you really need a lot of planes well scattered over the span of the war.
I think the RPS would be a nice complement to the perk system......early in the RPS, perk planes could often be one of the later model planes that started out in small quantities, limited combat, etc...or planes that existed in small quantities, like the C Hog (I'd like to see the C Hog as an easy-to-get perk plane someday.)