A quick story...earlier this month, eight of us went out to hike Indiana's longest and most difficult trail, the Knobstone trail. Trust me when I say this state isn't all cornfields, this trail is ridiculous and is notorious for making people quit before reaching the 50-mile ending. Well, I was the only one who finished. Everyone else carried osprey packs with more traditional gear. Their starting pack weights were in the 30-40lb range, while mine was 17lbs. I realize that there are many other variables, including physical condition, but I strongly attribute these results to pack weight.
So...since there are a million different aspects to lowering pack weights, I want to focus on the one I feel is easiest and one of the cheaper options, especially compared to shelter, that's the pack itself. Two of the people who went are close friends of mine. I have tried to convince them to replace their Osprey's with something that can save them 2-3lbs and will still be comfortable. After trying on a couple of my UL packs, I lost the fight. They stand firm that their Ospreys are more "comfortable".
I want to emphasize that comfort in your living room or in REI is only face value. True comfort, in my opinion, is the one that balances low weight with living room comfort. I started with an Osprey Atmos, then went to a Gossamer Gear Gorilla (basic internal frame) and now to a fully frameless pack. Is the frameless pack as comfortable as the Osprey when standing in my living room? No way...but you can't stop there. The above hike was my first hike with my frameless pack. What I did notice was that I was a lot less tired. Let's face it, if you have ever done a truly difficult hike, the last thing on your mind is how cushy your pack feels, it's probably how tired your legs are, right? This is what you need to think about when picking a pack. Of course it needs to meet your requirements for volume and how much weight the pack can hold, but finding the lightest pack that meets those needs can save you weight and will actually be more comfortable in the long run. Fully frameless might not be for everyone but there is a middle ground (Gossamer Gear for example) and many of those packs show up here on Massdrop. If not, request a drop for one!
I would love to hear any insight or stories that other folks have to offer on their experience with switching to ultralight and what their experience has been.