I fly Crow on a my Comp Arf Flash (s), both the classic and Utlra. But I have never found the need for crow on my Comp Arf Viper. I do have a mix to give me a bit of up elevator so that the plane presents with a bit of Alpha on final but that is just preference. I fly out of a 400 foot strip and I will admit that it is a challenge managing speed when landing with little or no wind, especially with the residual thrust of the Rhino 200 I am now using. May be some crow in my future just for that reason.