I have an aerobic rider that is the only kind of cardio machine I found that I could do and get it done. I saw one on TV the other day being advertised (a similar thing) by Suzanne Sommers, I think. I did not pay attention as I have one.
I have 2 friends who bought the Gazelle. Both Gazelles are sitting in their garages. Don't know if that means anything. My aerobic rider sat in the garage for close to 10 years unused.
Go to a sporting goods store and try an aerobics machine that you can do for enough time to count. THAT is the machine for you!