Stain removal on glass

For those that do a significant qty of hard water spot/oxidation/stain/haze removal on large panes of glass:

Do you prefer to use CC550 or Safe Restore? Or another product? and why?

I don’t do large quantities but it’s best to start w/ a milder chemical like A-1 or MDR and then progress to SafeRestore w/ CC550 being a last resort.