What % heat reduction can I expect from the IR-8360?

Based on the spec sheet found on the product page (also linked below) about 50%. Keep in mind that a light film like this works through absorption and not reflection, so the actual glass may feel warmer than it does with no film, but it's keeping that heat from passing farther into the room. https://www.decorativefilm.com/mm5/graphics/00000001/UltraCool-IR8360.pdf