You got something mixed up there.

The Cuin rating is the "fillpower", as it tells you how many cubic inches (cuin) a certain weight (1oz I guess?) of the down will fill.
So,1000cuin is the best there is, but 650 to 850 are more common.

All the jackets listed have a 90/10 or better ratio between down and feathers and most are afaik goose down.
Also, all have zipper baffles but none is a boxwall construction. I guess, that's not common with these lightweight jackets.


You should definitely check out Mountain Equipment, they have superb quality products at reasonable prices. Not a company to bombard you with ads like some others, but definitely one to consider.


The rab infinity G has nikwax treated goose down, but only a 7 denier pertex quantum fabric. It's very delicate.
The Mountain Equipment jackets all have weather resistant 20/30/40 denier nylon shells but untreated down inside.

As a last resort, I can always put my gore-tex jacket on top.



P.s.: I don't own all of these. I ordered them and will send all but one back once I made my decision. We don't have any stores where you could find more than two of those big fluffy ones at once.