I've been shooting L-mount since the original S1 launched and honestly, weight management is a safety issue when you're hiking the Cascades. Over the years, I've seen too many people compromise their footing because they're carrying top-heavy kits. The 24-105mm is a tank and that f2.8 pro zoom is just impractical for trail work. In my experience, you need to prioritize a balanced center of gravity if you're doing serious elevation. The middle ground you're looking for is the Sigma 28-70mm f2.8 DG DN Contemporary. Its the lightest f2.8 zoom for the system and the build quality has proven very reliable in my time with it. You give up that 4mm on the wide end, but your back will thank you after five miles. It doesnt feel like a brick hanging off your neck. If you can live with a slower lens, dont sleep on the Panasonic Lumix S 20-60mm f3.5-5.6. I know it looks like a cheap kit lens, but its weather sealing has held up for me in some pretty nasty conditions and the 20mm focal length is actually better for mountain shots than 24mm. Tbh, i usually bring the 20-60mm on long treks because it keeps the kit light and predictable. Going heavy just for the sake of specs usually leads to more frustration than better photos.