I use Xtreme brushes for everthing, first cleans, builders cleans, conny roofs, gutters etc etc.
Never noticed the slightest difference in scrubbing power compared to the bigger brushes.
Used to use super light, supreme and even ultimate, but have not noticed any difference at all in how quickly and effectively I can clean windows. The Xtreme, for me, does it all, it’s light and easy to use, so I’ve never bothered using anything else since.