I think a backpack or trolley would be a great asset to a vanmount. If you have one of these pumps from Gardiners
you can then fill a backpack from your tank in just a few seconds!!
I find alot of jobs I have the hosereel is more hastle than its worth and just quickly filling a backpack or trolley and taking it to the window would save loads of time. Sometimes the hose can be so annoying, having to go back and find where it snagged!!
If I was you Ian I would hold onto that trolley and buy one of those pumps from Gardiners, that way you dont need to carry any containers, If you save only 20mins everyday for windows that are trolley/backpack friendly then in a year that would be 86 hours in a year for a full time window cleaner, at £25 an hour that is £2150!!! I think the trolley is perfectly capapble of saving 20 mins every day on a domestic round even with the occasional commercial round, it obviously does depend alot on your own circumstances though, Luke