Deep frying cooks by conduction through hot oil. Cyclonic air cooks by convection. The results are close, but they are not the same, and the differences are worth knowing.
What gets better
Anything with its own fat — wings, thighs, halloumi — renders and crisps beautifully with no added oil at all.
What needs help
Dry, lean foods still want a teaspoon of oil for colour. A spray bottle beats a drizzle every time.