Simon,
it was not my intention neither is my intention to have a go at the rx, as you have already asked ,Have i used one the answer is NO, but I find it amazing that people state that carpets actually stay cleaner for 3 times longer, especially in a night club :

when a rx has been utilised, and that statement is coming from a guy who,s web site states
" . It's so effective that nearly every carpet we clean looks once again just like the day it was laid, no matter how dirty. "
"Whatever the condition of your carpets or furnishings, no matter how dirty we can usually restore them to looking 'Just like New'." etc ect,
no sign of an rx on his site :

but their is a pic of a prochem wand, with the same two people who seem to work for an awful lot of people

Come on get real rx does not clean any better than most competant c/c with adequate machines all it is imho is an overpriced, unnecessary tool and it certainly doesnt have the added feature of preventing resoiling 3 times longer than a normal wand, re soiling problems occur for any variety of reasons!!
Hydramaster rx20 , no doubt a nice peice of kit ,but not what some are trying to make it out to be!!
Yes , I do like hydramaster I use the dri master.
geoff