The set up which works well for my situations is;
500 litres of water (pre heated with an immersion heater and water at start of day at 68 degrees c. Stored in a well insullated tank and it holds it temp all day.
It pumps out using one pump a sureflow 100psi pump via a pure freedom digi controller. For maximum heat at the brush end, i have a flow rate of 80.
Brush: i use a dual trim slime line mono filament brush with four pencil jets (which i have posted pictures on here plus a video to show the hot water,)
Its a heavier brush, but personally i like the weight and also little spread of the brush.
Because the brush doesnt spread, the filaments dont disturb the seal and i can run the brush along the top of the window to cut in (trad term i suppose) once that is washed along with the frames i concentrate on the window and the rinse is just below the top seal. Due to hot water and a higher flow and i clean every four weeks, mostly it only requires one agitation on the glass and then rinse. But on a flow of 80, the firt pass is a scrub and rinse in itself then followed by a second rinse.
Provided the frames are clean and your technique is good, ive not had a complaint yet and yes many a times in first yr of switching over i was paranoid about the cleans and as im fortunate to clean house after house on the same street. I often went back after windows had time to dry to check the results. Ive not been let down yet