I would ask @Matt about his experiences with the Carinthia Defence 4 but I am also aware that @1 shot willie quite liked it !2nd hand Carinthia Defence 4
British Army Arctic 90
Dutch Army M90
British or American Modular...
(all synthetic, all fairly bulky and heavy. All strong and warm!)
would agree with that 100% ..All down to personal choice..... But I can say I enjoyed some warm and non restricted nights in the Defence 4.
It is well made and the zip is quality.
The design of the bag may not suit everyone because of the snorkel type hood.......personaly not a problem for me.
Only reason I sold mine was needing more protection due to the meds I am on.
In all though it's a good bag and worth considering if you think the snorkel design would suit you.