hi james i use a variety of brushes.i find the sill brush soft(black)ideal for leaded windows and wooden georgian windows.
the sill brush medium(white)is good for conny roof/fascia cleaning and dirty first cleans where the frames are minging!
and the medium extreme brush is ideal for high level work using my 40ft supermax due to the sheer lightness of the brush.
i also have the standard supalite dual trim brushes in both the soft and medium bristle but they dont get used as often these days.
my vikan standard brush is now only used on a short pole for cleaning my van and car!!

best wishes
dazmond