When you're hiking for a long time, what size pack do you like and what do you sacrifice/gain from it? If you pack light, what would you bring in addition if you had a bigger pack?I have a few packs and I'm trying to decide which size to aim for (not really sure if I should decide on a pack first and work with what I have, or decide what I'm going to bring and then find a pack to accomodate it).Let me know what you think..