I haven't read this whole thread, but I do have 20 years experience with OP. Today I was called out to one of my best and pickiest customers. A retired OBGYN, former Admiral in the US Navy who delivered 2 of President D W Eisenhauer's kids and did a historectomy on Mammie. This guy has a Southern style estate here in the desert, and I've been servicing his 27 year white carpet for close to 20 years with OP. He can afford to hire anybody he wants to, and he doesn't do business with people out of pitty. He credits me with extended the life of his carpet, and it has not been easy, but I have done it with OP!
I will explain it in this way: You can spray a car with soap, hot water and risne it, but what remains is a layer of grime. Until that grime is wiped off, the car remains dirty. When I OP, I spray, pad with a damp pad, then go over the area with a dry pad, then another dry pad. If it doesn't look good to me, I re- spray and go over it again with more pads until there is no visible transfer of soil on the pads, and the carpet meets my visual approval. The pads remove that layer of grime. I use my own cocktail of reputable products, and achieve extraordinary results, or else people like Dr. Wilson would not give me the time of day.
We can argue who's better, but it really doesn't matter, as long as I'm providing my customer what he wants, and nobody else has been able to provide that for him.