Dakkajets with Fighta Ace can do fairly well vs Vendettas, actually, and it's all thanks to the twon-linked guns and Waagh turn. See, on turn 2/3 you point each Dakkajet at the nearest squadron and declare Waagh,then unleash 18 twin linked BS3 S7 shots against an armor 12 squadron. They may not all instantly die, but you will do massive trauma and destroy several. then you throw in any other Ork shooting units with decent strength, which hit nearly twice as well as most other units thanks to their high rate of fire weapons and already terrible ballistic skill being nearly unaffected.
Stormravens honestly aren't the worst things on the table. Necrons have a nasty counter (guess what happens to his HQ unit when everything else is in a dedicated transport? Guess what happens if their are no enemy models on the board after turn one?). Imperial Guard are truly aggravating now due to the fact that they NEVER have a weakness after the Vendettas pick the extra troops up on turn 2. They can shoot tons of anti-tank, anti-infantry (heavy bolter sponsons and hover mode!), and carry scoring units. Dark Eldar are even stronger plexiglass than they were if you take either jet with lances.
Every codex without a flyer, especially Tyranids, is now boned vs. all flyers.