Another point to add is that we could all be posting videos comparing our speed, technique etc but there's so many factors that determine how quick we generally work.
Window type, glass type, location, time of year, new customer ( trying to impress), equipment used, flow rate, even the temperature ( I personally work quicker in the cold).
There's no way I could use the technique in that video in the round I done today.
All 4-5 bed houses, leaded hydrophobic windows in a woody location. Windows were thick with cobwebs, snail trails and those annoying yellow pollen splats.
