I have no real issues with this thing -- used it about 3 times. The higher the intensity, WATCH OUT -- it HURTS. As far as toning, I think I'd have to use it ALOT at level 99 to really do any actual "toning." At level 75, I feel myself hunching over as it contracts my stomach muscles, perhaps I just need to get used to it! Overall, I find it neat and if it actually tones, well great!