In reply to Scarab: eeerm cant answer that.
Right... weight for warmth of down, need to know fill power and fill weight
Primaloft overlays are 60 GSM
This is rough....
assume basic shell and lining weigh the same
Rab has 220G of 800 (us) fill power, unless its older model, so shells weigh approx 400g, weigh your rab it wont be 600g
Berghaus weighs a kilo, -400g for shell, - say 150g for primaloft (2.5m)
extra material internal for baffling and separation 200g, so are we saying 350g of down?? doesnt sound right, maybe 300g of down, 700 fill power,
So from that I would assume that an incinerator jkt is as warm as a rab neutrino endurance and a rab generator smock combined, which would weigh less and probably pack smaller.
Alternatively just take the neutrino, it will probably be warm enough for ice cragging in norway!
HTH geek out