I have never said these machines are not capable of doing a good job, but surely it's about making the jobs easier and quicker, so you can get more done.
I could drive from lands end to John o Groats in a 2cv it dont mean i would want to

when i could go in a S Class or Beamer

But the equation that if you have a bigger carpet cleaning machine it will cost more money does not add up

If you have a bigger more powerful machine you can work much quicker and earn much more money doing the big houses where you need 75 ft hoses, thats the one big diference i have noticed with the Airflex triple vac you work you way across carpet much quicker, than i did with even the twin vac so a single vac well never used one, but sure it probably does a good job but a truckmount will be on his third job and i will be on my second by the time you are packing up wheres the financial logic in that, unless your doing it part time for a bit of extra cash then it would be fine