Clo per ounce...

I don't agree with this table. It is very misleading.

clo/oz
Cotton 0.04
Merino wool 0.08
Polartec 100,200, 300 0.16
Polarguard 3D 0.63
Exceloft 0.68
Polarguard Delta 0.68
Climashield HL 0.68
Down (550 fill) 0.7
Primaloft Sport 0.74
Climashield Combat 0.79
Climashield XP 0.82
Primaloft One 0.84
Down (850+ fill) 2.53

It shows merino wool at 0.08 clo/oz and Down at 2.53 clo/oz. You certainly won't save 30 pounds of wool with a 1 pound down jacket. You might save 1 pound on a total clothing system of 5 pounds vs 4 pounds, for the same warmth in dry cold, but the 2 pound wool sweater would better for the cold wet freezing rain.

All winter clothing systems are about 4 clo or 6 togs per inch. A full inch of loft is a pretty heavy duty winter system, perhaps 6 pounds not counting your shells and footwear. Your not going to shave off much of that by using down until you go well beyond 6 togs. You might save 0.5 pounds for every additional tog beyond 4 togs. Not sure. But how many togs do you really need?
7-8 pounds including footwear and shells for 6 togs is already alot of clothes, and I think down only saves a pound tere.