I just bought a nice down sleeping bag for my fast approaching thru-hike. All my past bags have been synthetic fill, and i was wondering about how to take good care of this one, particularly, how much compression is appropriate for a down bag. The bag I own is a marmot helium. How small do you think i should try and compress it? It came with two stuff sacks, a large size, and a small size, which further confused me. Of course, I know not to store it in any thing which will compress it at all, but when i'm hiking i'd obviously like to get it as small as possible without risking damaging the down. Are compression sacks a very bad idea for a down bag?? I know it may be hard to give me a good answer without actually seeing my bag, but i'd be very interested in any input. Thanks.