My 2p worth,i have a Prochem powermax with a 120psi and not the 70 psi it came with,did a job yesterday for a lady,just lounge and hall,she knew her onions,and told me her dad did carpet cleaning for 30 odd years,and then her brother left the building trade,and started up,both of them used truck mounts !
She was a little bit dubious when i unloaded my machine,and asked if it was going to be up to the job.
Of course i said,seen and cleaned much worse than this.
Cleaned as normal,got great results,custy over the moon.Moral of the story is ,it`s not all down to the machine,but how you use it,and attention to detail