Barbour puffa-style coat - is it actually warm?!

[Fillybuster]

I’ve just bought a fairly spendy (for me) Barbour coat to replace my much-loved but totally-falling-to-pieces 8 year old Mango down-filled puffa coat. The label tells me that the microfibre filling is warm despite being super lightweight but the coat is so thin I can’t really believe it’s going to provide proper warmth!
Does anyone have one of these? How have you found them?
This one

Bumping in the hope someone will be able to let me know!

I have that coat and find it very warm. I think it is the type of filling which determines the warmth. I have a much thicker and heavier Zara coat which is not as warm as the Barbour.