I also received the kit today! What is useful in my background is the fact that at 18 yrs. old I owned and operated a janitorial company. At 24 yrs. I sold, happily, and continued to develope small housecleaning services while growing a family. The point is, I know cleaning products inside and out. We tried the Pakit glass cleaner on a (embarrassed) very dirty sliding glass door. I used 1 liberal coating of glass cleaner and 1 clean cotton towel, inside and out. This was around 3pm facing south. So far, awesome results, clean and no streaks. In the morning light I will check for streaks and report.
note: I know what to expect from Windex and will report accordingly. :)