TimP, I think you are missing my point. Cleaning comes first...period. Then, if they perform at the SAME level, cost and dilution rate apply, but ONLY when the cleaning is equal. That is why I brought up the economical use of Extreme Clean. It is around 30 bucks and dilutes at 2 oz per 2 gallon of prespray. Some presprays also require heat to help it dissolve or become effective. Extreme Clean does not.
This is not my first rodeo and I have managed to own 3 sucessful businesses, (some going strong for over 25 years) by watching the bottom line but quality is ALWAYS my FIRST consideration. Quality of service and end product is what sets you apart from the rest. My second point was that different cleaners seem to work better under different region's soil conditions and also seems to be a personal opinion as to which cleaner to use. I was merely making my own observation, not claiming to have all the answers.
My personal experience has been that Extreme Clean cleans as well or better than anything I have tried on nasties, and is more economical, but I am not afraid to boost a cleaner regardless of the cost. If it can give me a better clean in a shorter period of time, that will be my choice because labor is the biggest cost in a service business. Why do a half-ass job when a dollar worth of cleaner will make you a hero? Why waste another 15 minutes mixing a new batch of prespray with another product or boost because the first batch didnt get the job done?
Time is money, mix the prespray right the first time, get the job done as efficiently as possible, become a hero, collect the check and referrals. Choose a prespray that works best for you after testing them side by side. If they are equal, choose the product that cost you less money. That formula equals $$$$. I think we are arguing the same point here.