I wouldn't be afraid of the HMG, especially for your use case. I've got a ton of time under one, and if they fit you well they will carry a lot of weight quite well, especially if you pay attention to how you pack. I've hauled >80lbs(science is fun!) in a HMG 3400, definitely not recommended, but I would say that if you're average load is under 40 and your max load isn't much over 55 you would still be happy with it. That being said, I also own a Seek Outside pack, and I would seriously look into them if I were you. A fair bit less money than the kifaru, lighter than the kifaru, carries weight better than the HMG, more customizable fit than the HMG, and just as waterproof as both. I'll never buy a pack made of non-waterproof material again, for me its less about keeping the contents dry, and more about the pack itself not soaking up moisture, gaining a bunch of weight and soaking me for days after it gets wet.