Firstly let me say I'm fussy. And I don't mind spending money on something that works. But it better work.
Castelli never let's me down. I love this brand.
This garment (I bought 2 this season to add to the 2 I bought 2 years ago) is excellent. It's surprisingly warm. As MSA1288 said, I wear it under a thermal jacket and I'm good to go for a frosty morning. I wear it running and cycling.
I am castelli buyer now. They just make good stuff. Buy a size bigger than you normally do - and it'll fit like you always dreamed of - maybe even better.
I have these and the castelli long thermal bib knicks, short bib knicks and the short knicks. Man I just love their clothes. Now I don't mind winter at all. The clothes made me enjoy it.