Factory insulation vs. Dynamat, etc.

These aftermarket insulation products with the aluminum facing seem to be only about 1/16 inch thick. My Mopar factory stuff must be at least 1/2 inch think, maybe more. My question is: which in the long run is superior? I am ready to reinstall a dash frame and have been debating whether to replace the 45 year old yellow factory insulation (what is that stuff anyway, fiberglass maybe?) with an after market product. I would think the thicker (factory) the better.