Different tools for different jobs.
Original purpose of these tools is as below:-
The Omnitrolly was originally designed to carry out cleaning in lightwells in Hospitals,Colleges etc. where accesability would be impossible using trailing hoses from van mount systems.
The Backpack was introduced to carry out inacessable windows on the outer areas of larger commercial contracts where the setting up time with a van mount would take longer than the window cleaning itself. In saying this Jeff Brimble has been using a back pack for many years on all his work.
The Trolley system has now been adopted by mostly domestic window cleaners and due to the amount of water held in a tank they can operate between 30 minites and two hours between refills depending which system you operate.
The backpack allows for only 15 - 20 minites between refills and is fine for domestic work where you can park your vehicle close by for refilling.
Trolleys are very suited to cleaning shop fronts where you have park a distance away.
Glyn