So...I had a little surprise waiting for me when I got home. I have to say that I am incredibly impressed. There are some things I wasn't expecting, both good and bad (trying to be neutral here).
-I've packed in 24 discs: 19 upside down like the Simian in the six slots (4 in the top, 3 in the rest), 3 in the front outside pocket, and 2 in the tongue half pocket
-The side pockets will hold two discs each (they're stacked but locked in place - shook the bag upside down without them moving)
-The frame is sewn into the side of the bag, but there is the room behind it as wide as the frame
-The removable lumbar piece is nice and thickly padded but the strap is 1" wide. I would've liked a wider strap like most hiking packs.
-The main compartment wedges down to the part of the bag that touches your back. That space means more room in the inside front pocket.
-The straps are well-padded and almost four inches wide. With an empty bag, they pressed against my neck. Fully loaded, they spread out enough that I couldn't feel them.