Let me predict the responses from the Ultra owners (like myself!):
The RK is a FINE bike! In fact, a FANTASTIC bike!
But add a few creature comforts, (and you don't me to list them, all the other guys will), and TAKE OFF the "pizza box" when you're not doing any real traveling, (the quick de-tach kit has relegated a great many tour-paks to the garage, never to be seen again), and you have everything the RK offers and more!
Note to all the RK guys:
Yes, actually, in very many ways, the RK is a completely different animal, and my insinuation that they are only differentiated by a fairing and tour-pak is silly. Just having fun here! Either bike is, in a word, WONDERFUL, for 2-up riding. But I have to also point out that if you haven't ridden an Ultra, don't believe based on looks it is only a 2-up machine, and a long-distance runner at that.
With the TP off the bike and a low-slung seat and back rest for the passenger, it's as sleek and comfortable to handle and easy to maneuver as any of it's "smaller", (used only for lack of a better word) brothers!