I am considering a venus .40 and I want it to be very powerful in vertical. I am considering and prefer 4 stroke:

OS70
YS63
Saito72

I have searched on venus and read that the OS70 does climb out vertically but not with authority. I want to pull up vertically and with authority power up to the clouds. Nothing I have read comments on the YS63 and the Saito72 seems to get a bit better performance than the OS70. Does anyone have any suggestions short of an OS91 4 stroke. Although From what I am reading sounds like a stroker OS91 would not be too heavy for the venus and I bet this motor would rocket the venus. I just don't really want to go that big. Anyone use a stroker OS91? Any comments with vertical on your 70 class strokers?