The Cosmic is a thinner shell with no liner according to Chris at Trew. it packs up small, fantastic for backcountry. I know Trew fit sorta short their first two years, but i'm fairly sure they're longer now - not Saga long or anything crazy.
bellows is the thickest and bulkiest but they're all shells so they will all need layering. the cosmic is a backcountry parka whereas the bellows and pow funk are good hybrid jackets