In reply to chaude:
BD packs are really good. obviously designed knowingly.
i used a mammut ice 35 for 2 seasons and although heavy found it uk. lids a bit floppy. i clipped the belt behind it when i had a harness on. the buckles on the ice tool holders are too small with some gloves on and a pain in the arse, but other wise its ok.
nowdays for guiding and courses im finding the millet exped 65 is great. yep its huge, but cinches down dramatically and i take off the lid, i also ditch the frame.
what attracts me to it is the full-length entry zip. easier than anything else to access stuff fast, especially when hanging at belays.
then you jam the whole lot in and just cinch it down.
still only weighs 1.5kgs.