All good points D and Foo.
I think that 9mm is an acceptable amount. Perfect? Nope. But for $15,000, I can certainly live with it. I would rather have a watch that is 37mm, with a smaller movement, than a watch that is 34mm with a perfectly sized movement, all else being equal. I thought the movement in the Traditionelle Small Seconds was on the smaller side of things, but it certainly did not bother me.
You already have the Patrimony? Why even bat an eyelash at the Saxonia, then? I'd take your existing watch any day.