The Shift is certainly thicker and warmer than the Rime. Its a bit heavier, but the Shift is still a very lightweight jacket for its capabilities. The Rime is a perfect fall piece, and the Shift should be a fairly good winter piece, although I would suggest something with Insulation, such as the Backcountry.com Primaloft Siphon Hoody, for a winterpiece, as its going to be warmer.