I used mine faithfully for a couple of weeks. I could already tell it was doing me some good. I had it in front of the TV, so it could be done without extreme boredom. I used to watch Alex Anderson's show and Carol Duvall. The problem was that those shows made me eager to do things that couldn't be done while walking on a treadmill. We still have the thing about 13 years later, and neither one of us uses it, but we always think "maybe someday". I have a feeling that someday may come when one of us has a heart attack, if we're lucky enough to still be able to exercise after that! Meanwhile, the overweight cat looks kind of cute lounging on the treadmill. It's not motorized, or at least she could get some exercise on it (assuming she might!).
There's a neat website called instructable.com. The young people who run that have devised special desks to go on treadmills allowing them to walk while working on their computers. They say they can't go very fast (about 1 mph, as I recall), but it's a lot faster than I'm going at the moment. They have instructions for making one of those desks. I keeping thinking it would be a good idea.