A good example, Alex.
WFP looks more 'professional' and 'up-to-date' for the larger jobs and has some advantages for other types of property also - but I'm convinced that you have to use more water and spend more time on the job than some of its 'fans' admit.
And its biggest disadvantage is that, most times, the cleaner is not there when the windows have dried to see the results - so he can't rectify them.
That is why cleaners get complaints and why some concientious/perfectionist cleaners aren't 'madly in love' with WFP and are not in denial about some of the 'problems' associated with it.
Mike