This is something that seems to be nothing more than a matter of personal choice for most of us. As for me, I use what came with the pole, not really understanding the different applications of the different brushes. With my current brushes I find my self often changing the angles of the brush head to give the sills on a first clean a better scrub but would I not solve this by buying a sill brush instead? (Previous question based on the fact that 90% of my work is typical residential double glazed housing. Just looking at Gardiners site and in the Super-Lite brushes alone we have a choice of: Medium mixed bristles - Flocked Bristles - Stiff Bristles - medium mixed bristles - Splay flocked bristles. Can anyone explain the actual practical application difference? I'm sure someone could enlighten myself and some others here, perhaps a word from Alex Gardiner himself.