I know that my business and marketplace are a little different to the norm, so perhaps I can afford to work this way, so here's my view.
We are the experts in our field. He have had the training. We have made the investment ito our business'. We know the systems and chemistry. It should be a technical decision on our part as to how the carpet should be cleaned, whether this be VLM, LM, rinse/extraction or a combination system. The prospect is not qulaified to choose which is the best way to clean any particular carpet. We are. The days of 3 days drying for a carpet and 5+ days for a suite are long gone for professional cleaners, so short drying times are not really much of an issue.
As already discussed above, options are best left to add on products and services.
I know the counter arguments, and whichever way you look at it, they will be put forward as a tool to close a sale. By offering "The best clean only" isn't about one system or way of working, it's about using the most appropriate system(s) for a particular installation and executing it to the highest standard.
Fire away, I've got broad shoulders
Safe and happy cleaning
Ken