So today, I took some paint cleaning clay and clayed my windshield. I would say on a scale of 1 to 10, (10 being very dramatic improvement) I saw about a 7 in terms of improvement of reduction in glare on the commute home.
So it was certainly worth the 20 mins I spent, and I'm glad I didn't have to go thru the time and trouble of a complete windshield replacement.
Thank you everyone.
(especially BJSC)