I did look at at a Dynamax a couple of years ago but thought they were just an over priced very cheap rotary and there are better products out there,
my Chemspec Chemstractor cost twice the price of a Dynamax but its was worth every penny, its twelve years old and is a five in one machine, built in sprayer for bonnet and encapsulation, shower feed with brush or pad, rotary shampoo with vacume extraction, it even cleans stairs with hwe and small upholstery jobs
a very versatile machine that was built to last, I have a Cimex and a Hos but they are very over rated compared to my chemstractor
Stuart