Hehehe. A friend of mine purchased one a while ago. Actually made a big deal of it, that he saved so much money over a gym like the rest of us. Of course, this very morning he tells me he's saving up to buy a complete set of free weights.
Simply put, the Bowflex and other machines like it are a compromise. They just don't give you the level of workout that a professional machine or freeweight set would, but at the same time it's less taxing on the bank account, and allows for home exercise.