All things considered Ian, your objective in choosing a pole has to be, surely, to work as effectively and as quickly as possible. The speed aspect of that statement is directly related, to a large degree, to the overall weight of your pole assembly. Put simply, the lighter your cleaning implement the faster you can work and then, obviously, the more money you can earn at the end of the day.
As my cleaning methods and alterations over the years have always been adjusted with the idea of promoting aspects of speed and ease whilst working I have managed to drastically reduce the time involved in cleaning windows.
It may seem insignificant, but working with one or two sections of your pole that are not required for most of the time is going to significantly reduce your earning potential through nothing more that the tiny amount of speed lost in moving the extra mass in each movement of that pole. It’s all physics man!
Work with whatever allows you to move as quickly as possible.
Nick