A new shipment of material arrived to work on. I've read many times here on the forum as well as in magazine articles that mass is an essential component to sound reduction which I have taken to heart so I decided to go with a double layer of 5/8" drywall on top of the 3/4" MDF on all vertical walls. The ceiling can only get one layer of 5/8" drywall on top of 3/4" MDF due to the roof being cantilevered. As such I have a weight limit on how much weight I should safely add per square foot. Knowing this now, I would have obviously requested a change of plans. Live and learn for the next massive house project I hope doesn't come for a very long time.
And, I've also decided to use three tubes per sheet of Green Glue which I hope will add a little "secret sauce" to the hopefully significant noise reduction ability. There is no such thing as overkill.
Moving all this material has been a bit of an unpleasant experience but hopefully it's all worth it in the end.
Here is my ceiling with the insulation in place. I used R-30 which is overkill (again).
Gains on using this incredibly thick stuff is likely minimal over R-13 but, heck, I've gone this far.... why not, right? Helpful suggestion to anyone reading my thread... put the insulation in BEFORE you put on the hat channel and clips. Holy cow, with all that sharp metal and tight fitting area, putting in insulation went from a fast and easy job to a VERY SLOW, moderately pain in the butt job. That ceiling took many hours to complete (I'd rather not fess up to how many exactly as it would be too embarrassing