This is the most innovative, fun but challenging piece of workout equipment I've ever owned. I'm a former cyclist and runner and had taken more to indoor and less impact but high intensity oriented cardio. I own a Versaclimber, Keiser spin bike, and stair stepper and while all are solid in their own ways, the Halfbike is the most fun and mile-for-mile similar to running but with a cycling leg burn. I ride it six days a week on a 9 mile route with challenging rolling hills and finally have a cycling/running feel and freedom without being threatened by cars and taking the impact to my ankles and knees. I couldn't recommend this bike more. I can't believe I don't see them more in the Dallas/Ft Worth area as incredible as they are. Do yourself a favor and get one (or more).