Steve, the first half of your post was good.
That said, where I think you're missing the mark is not saying anything abut Duality. Sure, couples of other intertypes can "make things work", as you say, but what is the overall quality of the relationship?
Put it another way, there's probably a good reason why everyone, for the most part, on these forums who has experienced Duality has only good things to say about it I'm not trying to undermine your post or anything, and I'm happy for you that things are so happy for you with your wife, but I just wanted to add to what you were saying.