Climashield synthetic insulation is great for wet/moist environments as it holds it’s loft, doesn’t absorb much water, and dries fast. It’s insulation value is much higher than fleeces/soft shells and it’s continuous filament construction loses very few microplastic fibers. A Cloud 71 durable mesh inner shell feels soft against the skin when moist instead of the sticky/clammy nylon shell materials. It allows for extremely fast dry time, as moisture can pass right through the mesh uninhibited. Since air can pass right through the mesh and the Climashield insulation, the only thing really inhibiting air transfer is the outer shell. You can select Argon 67 for around 50cfm, which is a good balance of windproof to breathability. Or you can select Cloud 71 durable mesh for 1000+cfm. This makes for a garment that breathes like fleeces, but with much more warmth for the weight. These work out to be about the same weight and breathability of 4008 Alpha Direct fleece, but with far more warmth and better loft retention when wet.
Wearing with a pack (zippered version only) -Typically, to put on your insulation, you have to remove your pack, put the item on and put the pack back on over it. Then once you do this, the insulation in the garment gets compressed under the pack and under the pack straps. These areas tend to get wet with sweat and the long term compression combined with the sweat oils pressed into the insulation degrades it heavily. The Climashield Pullover/Jacket has a top snap that allows the garment to be put on/taken off over backpack straps, without removing the pack. The jacket is put on backwards and snapped at the top behind your neck/over the straps. The bottom can be connected with the zipper by your lower back/below the pack, or tucked in without connecting the zipper, or left to hang along the edge of the pack. This leaves the pack against your back and the jacket cinched along it, but not under it, or under only a small portion. If you are wearing the jacket forward, the top snap also keeps the jacket secure while allowing you to open the zipper for ventilation.
If I had to bring just one insulating layer for most environments, this would be it. Super light, breathable, good ventilation, holds up in wet weather, dries extremely fast, and has enough insulation in the 2.5oz/yd APEX to provide inactive warmth too.