I rode a Rocket III several years ago, and felt the tank looked like an airport runway in front of me, although the bike was very easy to ride. Not sure I would want to have to back it into the garage after every ride...at least I don't think it would be as easy to back as my SM.
I did get a chance to sit on a Roadster a few weeks ago, and it felt much different than the original Rocket III, in that I felt like I was sitting ON the Roadster, not IN it. The tank stretched out below me, and I really liked it. I can't wait to ride one.
Then again, for a few more $$$'s, one could also get that Italian Diavel, which weighs less than 500 lbs....but still a roadster (I guesss).
