who knows..LOL
But ive found it good for drying clear, not smeared like washing up detergents, when detailing.
Yeah it takes getting used too with technique - but its obviously your technique giving your problems not the detergent. If you rely on glide to clean a window rather than proper technique your guaranteed to have problems using it.
That being said im no expect at squeegeeing (excuse spelling?)
The windows look cleaner after use, its doesn't give frames that green algae look after a few months, and it doesn;t attract dirt as much so the window will stay cleaner for longer.
Im sure guys out there using the fairy and similar stuff do so because it dirties the windows more, so after a few days they are dirty again.