How do you get more done in a day? Do you scrub less or rinse less. I can't see how it can be any quicker on maintenance cleans unless you physically miss something out that you'd normally do with cold water.
It's better on bird poo granted but the scrubbing action is identical on normal cleaning - you can't possible see the dirt coming off.
Its only a few house more not a great deal, but I find the warm water lifts any dust, muck off the glass and frames quicker, plus you don't need to scrub as much.
You should try it out on your own house, might be surprised on how little effort you have to put in at times on maintenance cleans, if you scrub several times only try a few times,
I personally don't think it make any difference to dirt/dust that has only been on the glass and frames a month or two. I cleaned my windows which haven't been cleaned for a few months with a SL flocked brush, cold water and rinsed on the glass to test the brush out, I did virtually no rinsing, and the windows came up perfect.
I think we tend to over think maintence cleans, worrying hot water, the brush that scrubs the best and rinsing enough, but in reality windows that get cleaned every 4 or even every 8 weeks have very little dirt, and it embarrassing how little effort is required to achieve perfect results.