The 800-fill down is seriously warm for how little it weighs — I've been stuffing it into my pack for hikes and barely notice it's there. It packs down small but still blocks the wind on exposed ridges.
Adam Z.★★★★★
Wore this over a tee on a 45-degree morning and stayed perfectly warm without any bulk. The 800-fill down packs down small enough to stuff in my daypack, and it layers cleanly under a shell too.
Kevin X.★★★★☆
Wore this over a t-shirt on a chilly morning hike and it packed down small enough to clip onto my bag once the sun came out. Only gripe is the fit runs a touch snug across the chest, so size up if you plan to layer it under a shell.