What is the Utility of a lightly synthetic-insulated Vest?

I carry a Montbell UL synthetic vest for use as a pillow and as an emergency warmth layer.  I always carry one more layer than I think I will need for myself or as something I could loan to someone else who needs it.

now that Nunatuk is making an Apex vest, I’m likely to add a lightweight syn vest to my quiver

Consider my acrylic felt poncho. It’s ultrawarm, ultralight, and ultracheap:

My Stoic brand anorak down jacket proved a bit too lean on my winter backpacking trips in the High Sierra so I added a homemade poncho for additional warmth and it proved to be a valuable piece of clothing and multi-use gear.

I bought some cheap acrylic felt at the fabric store and cut a slit in it. I drape it over my head by sliding my head through the slit, just like a traditional Mexican blanket poncho. When my pack is on, the pack straps (shoulder and waist) keep it all in place. It only weighs 3 ozs and cost a few bucks. Also, I removed most of the back portion since my back doesn’t need the extra warmth while my pack is on, otherwise my back sweats too much during fast paced hiking or snowshoeing.

After a full day of winter hiking, I placed my socks and trail gators in the poncho and sat on it during cooking time. The felt drew the moisture out of my stuff and helped it dry much faster. The acrylic breaths really well. When I need more core warmth while also needing wind protection, I wear my wind/rain jacket and stuff the poncho inside my jacket in front of my chest. I simply fold the poncho into a pillow, and shove it into my jacket over my chest! it really works great! Its super cheap, and only 3 ozs. I have also used it to cover my mouth/face to combat breath condensation during winter sleep.

This was my solution to buying another $200 piece of clothing. I think I paid $5 for the material and I’d argue that my poncho works just as good as/or better than a Polartec or Apex vest.

Vests are nice when you’d like to supplement an insulated jacket by layering underneath yet don’t want the bulk of two jacket sleeves around your armpits and arms. For example, during spring and summer I can get away with a down parka with 3 ounces of down, but come fall and winter I need more warmth from my jacket. So rather than buying a new jacket with more insulation I add a lightly insulated vest to essentially do the same thing. Might be a bit heavier overall, but cheaper and more versatile since I can split up the combo during the trip if needed.

I made a synthetic jacket, and then cut off the sleeves because I didn’t like the contriction

I wear base layer, vest, WPB jacket down to 20 F