The reason it is quicker is because you will have far more confidence when you`ve cleaned a window and walked away from it in the fact that over time you`ll begin to realise that all that scrubbing in the past you used to do with cold was not needed,so why will you be quicker you`ll be quicker cos a couple of scrubbs on the glass with the brush on and you`ll know it`s clean.You cannot compare a cold system to a hot 1,when your using hot and i mean hot water the difference is massive on any type of work.