I have used this scooter for three years. I use it to commute to work, about eight miles each way, and it takes about 35 to 45 minutes. It gives an all-around workout much like cross-country skiing. It works the core, glutes, quads, hamstrings, calves, shoulders, and arms. It's different than the previously reviewed Xootr in that it handles and reacts more like a bicycle - and it brakes more safely than a smaller-wheeled scooter, too. I own the more expensive and higher end Track model. It is made with aluminum and is lightweight at 14 pounds. I chose it originally because of it's efficiency and performance. They do make a more affordable Express model which is almost a third of the cost but comes with lower end components. As far as sizing, it's pretty much a one-size-fits-all type of design. If you're shorter than about 4'8" or taller than 6'2' or 6'3" you can adjust the size somewhat by using a different stem for the handlebars. So they accommodate a pretty wide range. I carry it in my car just by taking off the front wheel with the quick release. It's a lot lighter than a bike and doesn't have any of the associated grease from a chain, gears, or pedals. Because of this it easily allows for multi-modal transportation: on the days I do drive to work in my car, I park over a mile from my office and take the scooter in from there. When I go out on the recreational trails, people often want to know what it is and how it works. I have found that it's a great way to meet people! People often call it a "scooterbike" by many when they first see it. I recently joined the FootbikeUSA racing team. We are amateur racers and we do it because it's something that's fun and healthy. While racing the marathon distance (26.2 miles), I've averaged 16.3mph, and in a sprint, I've reached 22.6mph. -- Gary Schmitt [Note: For those looking for a more utilitarian version you can find one at Amish Scooters. They are made in the USA by an Amish family and come in three different sizes with a variety of different colors. Prices range between $170-$250.-- OH] Footbike Express $130 Available from Amazon Footbike Track $370 Available from Amazon Comment on this at Cool Tools. Or, submit a tool!