It all depends on how you, as a rider, define "Sport Touring."
Theoretically, you could toss bags on the rear of a 998 and ride it from NJ to California. Of course, your chiropractor will just LOOOOOOVE you!
I voted Falco. Though you could install risers on an RSV and get pretty much the same riding position. The reason is that I ride the twistiest backroads I can find. That tends to limit you to around 300 miles/day, unless you continue after dark. Handling and lighter weight count for a bit more than a hugely comfy riding position as well. Especially since you're shifting your weight around as you ride, and that keeps the cramps to a minimum.
If you're more county road/interstate minded, you can go a lot further. Comfort and luggage capacity become more important. This is what a Futura is made for: 600 mile days and more (for you Ironbutt types). The bike's heavier and doesn't have the suspension/geometry for serious scratching (though you can hustle one along at a pretty serious pace, even two up).
Compare these to a VFR (which I owned prior to the SL): the Falco is MUCH sportier and the Futura is a better tourer.
Just MHO...
Scott :)