Before we got the Madsen we had a bike trailer and I can count on one hand the number of times we actually hitched it to the back of our bike and put our kids in it to ride anywhere. The pieces were stored separately in our garage and it was a hassle to set the whole thing up. Our youngest wasn't able to ride in it either, since we would have needed an additional infant attachment to secure him. The Madsen eliminates the need for extra accessories and setup plus it accommodates multiple kids of all ages and weights unlike trailers and seat attachments that have weight limits and age restrictions.
I also like that the bike is all one piece, so even at 7.5 feet long, it's easier to maneuver, park, and secure than a bike with a trailer attached. The bucket is as wide as the handle bars, so you don't have to worry about an attachment not fitting or following you where you ride.
Also, it's way cuter.