This experience is a blast! Where else can you lean back on your own fat boy and cruise the City without a license to ride? Granted, they top out at 20mph and your guide takes pretty good care to make sure you don't end up in crazy bad traffic.
We went out on the morning trek with Justin. He did a great job teaching us the basics before we hit the road. It is important to remember this is a 'tour', not just a ride. Consequently, you make several stops during the tour to dismount, chat and take pictures. In addition, you only move as fast as the slowest rider. Unfortunately, they don't subscribe to the theory of Survival of the Fittest.
Justin did a fine job explaining little factoids about the city as we tolled around. Our group was most intersted in scenery and music, so those are the sites that he spent most of his time on. The only regret I have is I would have liked the option of cruising around a bit on my own at the end and just letting the bike fly down the streets. I think 20 miles per hour may be understating the performance of these beasts, but we never really had a chance to find out.