Thanks for your comments everyone!
@ Jerry, I haven't noticed down leakage or condensation with the M50 quilts I've made before. I used a summer quilt made with M50 for the shell and liner last season, I don't remember having problems with condensation. Do you mean condensation inside the down chambers? A small amount of down has made it's way through a pair of booties I made using NoBul 1, although they probably get more abuse than a quilt.
@ Daniel, for the middle chambers I first sewed the entire baffle system to the shell. Then I sewed all of the baffles to the liner except the horizontal and vertical baffles on one side. Next, I started by filling each of the large middle baffles one by one then sewing the corresponding vertical baffle at the end to seal it and the first side horizontal baffle. This way I could more easily access the next vertical and horizontal side baffles after filling the next large middle baffle. In other words, what you said. . .
@ Michael, after staring at a sewing machine for too long I can't wait to get back out on the SHR!
@ Ryan, thanks, I had no idea what I was getting into w/ this one. It probably took 4 times longer than usual due to all of the starting and stopping.