i have 2 gardiner sill brushes.soft and medium bristle.
medium one gets used for fascia/soffit/conservatory roof cleaning
soft one i have on my 40ft supermax for solar panel cleaning/higher jobs with leaded windows
i use a medium extreme for maintenance window cleaning.very light and does the job!

i have both the medium and flocked SL standard brushes which only get used on filthy first cleans as i class these as too heavy for regular work now due to being used to the extreme brushes!!

so i have 5 gardiner brushes.i also have a vikan mono which is on a very short pole for cleaning the van!!
the extreme brush is what i use for most work though which is regular maintenance window cleaning.