I tried mine out the other day under a Klim Marrakesh suit, temps were about 7c.
It was comfortable and warm from the moment you put it on, no problem at all riding the bike, however when I got home I mowed the lawn and ended up sweating like a stuck pig!
I washed it through the machine @ 20c as recommended, it retained its shape and dried quickly. Pretty impressive piece of kit, enough that I’ll buy the cool version for the Europe tour next year.
Agree Steve, worn last Week over Peak District when temps got to around 8*. Just had this and tee shirt over the top and badlands jacket. As temp drops another layer would see this being my go to winter kit. As you say really comfortable and going to buy Mrs WD one for Xmas to see if she will stop moaning about being cold and wanting the heating turned up.