I would never go back to using ladders, I would pack it in first.
I cleaned windows in the 1950's using chamois mops and scrim, [still the quickest method for some jobs]
Squeegees then took over, but WFP is the best thing to happen to window cleaning in my humble opinion.
I get very few complaints, in fact I can't remember the last one, but then some people don't like to complain do they?
I know most of the guys prefer van mounted systems, but as most of my round is as compact as it gets the trolley system suits me better. A trolley system with two containers, and a mounted hose reel with 25 meters of micro bore hose. This gives me the best of both worlds, leave the trolley at the front and take the hose round the back.
You can clean a lot of windows with 50 litres of water, and not move the van once, and changing containers is quicker than moving the van, and what about parking issues?
If I had to move the van once for every two houses, I think trad would be more appealing.
I do a marina complex that only has pedestrian access on one side, I would need to run out 200 meters of hose to do it with a van mount.
I think in Paul's case it comes down to job satisfaction, or the lack of it, but a properly designed trolley could have made his life a lot easier.