No experience, jmanj, but your question caused me to look into it. There is a unit endorsed by Sara Meeks (who received no compensation). It is sold through marodyne.com LIVMD - Low intensity - and developed in conjunction with NASA for astronauts. The price I could find was $1600 and I don't know if that's current. Subsequently, I started looking at Vibration Exercisers at Amazon. I think I'm going to order one that is lightweight (many are heavy), priced at about $139.00 with a 5 year warranty. It will also work on carpet. Many don't. I don't need it to lose weight, just build bone density. My sense from the reviews is that many people who do not exercise buy these machines to lose weight. Most have a range of 1 - 99 levels of intensity. Some commentators, not on Amazon, said they could possibly cause fractures. I think that's possible for someone who's frail or using a high level of intensity. So I intend to use it on the lowest setting (walking). I just want to run it by the Physical Therapist tomorrow before I order. In the meantime, while I wait for stuff to heat in the microwave or make coffee, I jump up and down, do heel raises, march in place. Walk an hour everyday and just purchased 3 Carol Michaels DVDs - exercises specifically for osteoporosis. Thanks for raising the issue - I didn't know anything about whole body vibration machines.