I took a ride on on a Can-Am last year. I have to say it was much better than I thought it would be. I thought it felt much better than a 4-wheeler on the road. That being said, it would still be the last 'motorcycle' I would ever own. Yeah, you get the open air, open road thing. But other than that, you don't get any of the other benefits of a motorcycle (gas mileage, leaning in the turns, supreme manueverability, etc.
I do have to admit though that the one I road was fairly cool looking. He had different wheels, custom paint, etc. I'm not saying better than our bikes by any stretch of the imagination but not as bad as a Pontiac Aztec.