I regular clean my own windows and conservatory with pure water at oo, and there are always spots, ...
same with customers houses.... none of them are ever perfect, if i pass and stop to collect money, i can see a few spots on close inspection...and i wash all the windows really well.
I just dont think the finish on the glass will ever be better than doing them trad,but the overall results ...frames and doors etc,, and from a distance, does make it appear to look better...
and its quicker and makes us more money!,
but trad is far better for the glass clean.