I know I'm sounding like a scratched record (my kids don't know what that means), but I flew my Phoenix Extra 330 with the Saito 91 again yesterday. Quite a delight!
Next week if the weather is good, I will fly the U Can Do with the FA-82A again, but this time I will try the 14x4W. The plane already has unlimited vertical and hovers easily with a 14x6, it's just that I want to prevent any overspeeding with the 6 inch pitch. The U Can Do can flutter if moving fast.
Because The FA-91S has proven powerful enough for the Extra, I will not be acquiring an FA-100 for it. That will save me a few bucks, unless one of you guys is willing to donate one for the cause. I will probably use my Fox 74 on the plane I was planning on installing the 91S.