To double glaze or not to double glaze..That is the question

Hello fellow sound geeks. Let's play a game called - Help me make decision! I have built some killer doors for my new studio and am now about to set some glass in place. I have two options; 1 - The tried and true, double glaze system. One pane of 15mm and another 18mm (both angled) with an 60mm air cavity in between. 2 - I have a friend in the glass business who can get his hands on quality laminated 40mm glass left over from a previous job. Because of the thickness, I'd only be doing a single glaze, installed on a slight angle. Now, I'm pretty sure the double glaze way of doing things would most likley yield better results but I'm talking like a $600 saving if i go with the 40mm stuff. It's time to play dudes! What's the better way to go?

Saving 600 buckaroons is always a good reason to consider alternatives. Why don't you just "test" it. How is your current "super" door constructed? Are you using just one door? In that case it would not be the greatest loss to use one pane'o glass. you see, it all depends....