Hi Steve
Host is likened to the Rolls Royce of the counter rotating brush machines. Bit expensive.
There is Host, Envirodri, Flexi 5, CaretGard, and T4 - maybe one more cant remember.
These are the heavier machines that dig deep into a carpet.
A lighter weight one is the Sebo Duo - lighter on the pocket too at about £230, but wont do as good a job.
Joe