I can't speak from personal experience by holding one in my hand, but I saw one at hot springs this past weekend. From the looks of it, a single layer packs down small. I've been talking to Mac about maybe making a modular system for my BMBH and he says 1 layer would pack down to about a liter for a full-length bridge UQ.
I have heard your confession I know who you blame
If you had it all back you'd just lose it again
Can't bank on redemption if you ain't saved
Don't bring me your tales of temptation and loss
Don't bring me the pieces of your shattered cross
-- Stuart Adamson