Yeah...what Cannibil said about the double layer and pad retainment is very true...sure helps with pad. But if you have a single layer you can still make do, but remember YMMV. The UQ will definetly be an easier mode of under insulation. You can order some down from Stormcrow (just PM him) if you don't have enough after reclaiming the stuff that you already have to use for your DIY UQ project.
Great job on the first posting, welcome aboard lurker...just kidding!