First, i have experimented with ponchos and i didn't care for them, perhaps because we are often in the open up high and they do not work well in wind, even with a waist strap. Also, they do not have arms. I hike in the Pacific Northwest and it can rain here from time to time. Secondly, i think a pack cover does help enough to be worth it's weight IF you expect rain. It can be used for other purposes too like covering your pack and other stuff temporarily in camp. Thirdly, I put my extra clothing in a good smaller plastic bag, but not my first aid kit and food, which are in zip locks anyway. And I roll up my rain gear and put rubbers around them so I don't feel I need to pack them in a plastic bag....I'll probably be wearing them after it starts raining. I love an umbrella and take one often. Mostly because it allows you some cover to organize the pack, eat or change clothing. I have hiked without my rain jacket for miles under an umbrella attached to my shoulder strap with a carabinier. Conditions my very, your individual results may very.