It is a workout that is unparalleled on any treadmill. The exception to that rule would be a workout on one of the Incline Trainers from NordicTrack.
The highest end model when compared with the rest of the lineup is a heck of a machine. When you compare it to treadmills in this price range it is just so-so. You'd be better off with an Incline Trainer from NordicTrack. A $3,300 check will get you a heck of a treadmill from True or less than that will get you the brand spanking new X15i model from NordicTrack which blows the Bowflex away in terms of features and quality.