Before I had a sett of thin and fairly flexy fins for powered sideshore, some thin but stiffer ones for powered onshore and some thicker profiled fins for general underpowered sailing where upwind was a factor. Then , upsizing the thin fins to handle underpowered pwind didn work so well since you affected the turnability of the boards to much.
The Drakes seem to do less harm to the board even when used bigger so at slower speeds you can safely upsize them. If you sail powered up and at speed, the Naturals start to deliver more power and you don't need to use them as big. But at the same time they handle fast straight line sailing really well also when used big, so for x on powered up stuff where you fast on the way out but maybe not so fast on the wave, you can use the Naturals fairly big.
All these aspects is what made me sell all my other fins and just use a (big) quiver of Naturals.
BTW, the 06 EVO 70 can be seen in action in powered up 3.5 sailing (small waves though) in the movie link below (81MB) and in some cross on 4.5 sailing in Guincho in the pics on the second link.