Thanks for the EB fact sheet, for some reason or other I found it very interesting. I was surprised how low Milwaukee ridership was, but of course, it's part of corridor service so there are plenty of options between Chicago and Milwaukee. But it definitely looks like both ends of the route are crying out for another train or two, and probably corridor service.
Anecdotally, I can report that although there is fairly significant awareness of the Hiawatha in the Milwaukee market, there is much, much less awareness of the Empire Builder. To many in Milwaukee Amtrak=Hiawatha.