The RT and Road King are such different bikes. It depends on what kind of riding you're planning to do. If you are planning to do mostly one-up and like a sportier ride, the RT is the way to go. If you're planning a lot of relaxed, two-up riding over longer distances and if keeping your gal's tender buttocks happy is a concern, the HD wins.
I was making a similar choice this past summer. I decided that since most of my riding is commuting and the lighter weight is a plus, the RT was my best choice. I bought a 2010 RT and am loving it. For me, the novelty of a new brand was an incentive, since I've ridden Harleys.
Negatives for the RT: 1. Dealerships are few and far between. My nearest HD dealer is a mile up the road. To get service on the RT is a round trip of 70 miles. 2. Seat height (was an issue for me), unless you are a tall guy you won't be able to flat-foot it with both feet. That took some getting used to. 3. Supposedly expensive to service, although I haven't experienced this so far.
Negatives for the HD: 1. Around here, everybody rides them. 2. You look kinda comical riding one ATGATT... (looks more natural on the Beemer)...
Seriously, I'm happy with my choice. But I think there will be a bagger in my future, sooner or later.
