Many cleaners available today clean very well. The method in which we wipe the glass after spraying it can and does vary considerably. Paper towels, cotton towels, terrycloth towels, newspaper were just some of the tools available until the advent of Microfiber.
The towel plays a major roll in the final outcome. The new Microfiber glass towels work about 1000 times better than paper or cotton towels.
I use both Stoners and Meguiar's but I prefer the Meguiar's. For me it cleans better and is much more economical. I always dilute this concentrate with distilled water.
Tap or household water contains all sorts of minerals. These minerals are naturally occurring deep within the earth and are dissolved in the water. Even though your tap water looks clean, as it evaporates it can leaves streaks as these minerals once again reappear.
Meguiar's Glass Cleaner Concentrate
"Meguiar’s Glass Cleaner Concentrate is part of their Detailer line, a group of concentrated products intended for professional use. One gallon makes an amazing 11 gallons of ready-to-use cleaner when diluted with water as directed. It wipes away revealing crystal clear, streak-free glass. Since it’s formulated for professional use, you can bet this cleaner really works."