I have always believed that the Dry System, using mechanical-powered brushes and sponge-particles, is at best a carpet maintenance method that cannot reach the depths of the carpet or release heavy stains. Hence HWE is always more powerful, but at the same time can lead to shrinkage and, occasionally, unacceptable drying times. However skill, commitment and training can overcome these drawbacks, making HWE a good, reliable and (in particular) thorough cleaning method.
Regards
Pete (JS2)