I'm using the scale predominantly for PWV measurement. As far as body composition is concerned it is as unreliable as any other scale that is based on BIA methods. I don't trust it. The problem with the BIA scales is that they only measure the impedance offered to the current that they send through the body. The values are then compared to population averages which have been derived from comparing more accurate methods of body composition to the BIA methods. So, you have a large variance in these data, because a 100 kg bodybuilder has a different composition from 100 kg obese person (given the same height).

The PWV method is different, though. The ballistocardiographic method derives PWV from two different signals and relates them to body length. That makes the measurement far more reliable than the measurement of body composition. The scale's vascular age estimate, derived from comparing the PWV with population averages of chronological age, is affected by the same variance issues as the body composition. That's why we translate the PWV into a "rate of aging" that we developed from actual patient cohorts.