I would say that overall WFP does a more THOROUGH job, which does not mean better.
For me at least I clean the whole window, on large conservatories I wash everything form the gutters down, it really makes a difference.
On Georgian work or leaded then I would say that WFP is better, ok, yo ucan still get spots no matter what the style of the window, but these windows done trad will be flawed, when the sun shines at a certain angle these flaws show up.
On normal panes of course you squeegee away and they are fine, but again, get the light in the wrong angle and you can work out the squeegee passes.
WFP is certainly less CONSISTANT, and on most houses, if you look close enough, you will always find the odd window where there is a little trail of spots, and now and again you will get several of the windows wrong, it happens.
I work extremely hard to get my windows as SPOTlessly clean as I can, 95% of the time I succeed.
Some work comes up so well I cannot fault it no matter how hard I try, on others I know I am going to leave behind spots. Usually sash windows

(but not always!)
As for pricing and being a rip off merchant, well, that kind of depends on how you value yourself and the service you offer.
I watched a guy using WFP on the outside of the Lloydstsb in Chepstow today, and I thought he was dire, he didn't scrub the glass, he just passed over once and gave an off the glass rinse.
He also missed the one top corner on each pane of glass because of the angle he was holding the pole and he didn't touch any part of the frames either, not even the sills.
He had the long, grey fibreglass pole, so it was heavy and clumsy looking, and even though he wasn't very thorough in his work, he was still slower than I would have been and I always thoroughly scrub the glass AND frames.
When people work in such a way, it is small wonder that there are so many complaints flying around about the quality of WFP cleaned windows.
Ian