My mom bought one for me after she saw the infomercial.. The day it arrived at my apartment, i quickly assembled to give it a go. I have to tell you, the first couple tries, i was hooked instantly. It really is fun to do.. You can set it on 3 levels, from easy to challenging. The begining level is parallel to the floor, making it easy to get the hang of the swinging motions. The most challenging level is lifted vertical to the floor. After 20-30minutes of doing it and you definitely feel the workout.
It's a fun/easy exercise to do to work your upper body... As to whether or not it flattens your tummy from a 3minute session. Highly doubtful, but incorporating into your daily rhoutine should make a differene