I got an Osprey pack (20l tempest) and loved it, so now have a 40l and the 55+10. They are unusual in doing a women’s specific range which fits me really well- and I’d say fit is more important than features, especially if there’s an iffy back involved. Is there somewhere that stocks both so you could try back to back? Or order both and load them up at home to compare with realistic weight in? My tempest is now 10years old, has been used for winter MTB, skiing, hiking, travelling and is dirty but unbowed! Think I will get a couple more years out of it yet which is not bad going in terms of wear and tear given how light it is.