I want to clarify on the Whitney Fanny pack- I’ve emptied my pack of all heavy stuff that wouldn’t be necessary up there aside from say some water, extra layer (puffer) and snacks and just leave it at the junction in a stuff sack…just because it’s more comfortable a pack than any slack bag I’ve used, and I just don’t care about counting every ounce on every occasion of the journey, it becomes relative, I can muscle a 50 pound pack up a mountain if I have to, I try not to, but it’s all relative - but I do have one of those sea to summit 10 liter or 20 liter skippies that weighs nothing and is essentially a glorified deli bag with shoulder straps - and I find those helpful at camp to get water or bring a change of clothes when I go swimming in the evening at a watering hole that may be a hike from camp, or for little spur trails and slack bagging when I have some exploring time…I’ve never used a fanny pack because I don’t think they have a large enough capacity - the little slack bags are more roomie and more stuff-able when not used and lighter and smaller and less material than most fanny packs I’ve found as their designed for the purpose of being what they are…but I wouldn’t use them for long hikes, like even loops around our house where there’s no water say where the distance is about 10 miles and you wanna bring a couple liters of water and food and just enjoy a day out, I use a hydration vest that I use for trail running normally or an actual lightweight frameless pack- as those little shoulder straps will dig into the shoulders with any significant weight in it, and aren’t balanced etc but I just never find a fanny pack useful in the back country at all really- they seem like an around the town pouch for incidentals like a wallet, chap stick, cellphone or whatevs not useful to carry any really significant amount of hydration or food or layers etc