There are vast quality differences in windshield glass quality even within the the same windshield part number and manufacture. I recommend that before you have your windshield installed to carefully examine the glass for wave variations and also thickness variance at several points . Don't feel bad to use a digital caliper to measure the glass. Thicker glass does help with sound control however there is limitation to how thick (or dense and still comply with safety standards) a glass can go and still mount correctly on the car. On most MAZDA's the sound control is not really about the windshield anyway. We all know how loud they are when comparing other similar platforms like FORD. MYTH, OEM does not always mean it is the best quality glass. If you research you will find that MAZDA uses several windshield facilities in a few different countries.
Many auto glass will have a film of sorts on them and the installer should thoroughly and completely clean the glass as part of the installation. This is part of the customers inspection to make sure they get a clean glass with no film ,streaks or anything but a clean glass. If not you may miss during the inspection a defect or some other less desirable aspect of your new glass.