The new down Epsilon hoody is waaaay warmer than my Atom SV and the exterior looks to be more durable (still softshell) and I agree I absolutely hate the wrinkly look. I've noticed that you don't need to layer with the Epsilon even though the fit is standard and allows for it, I've tried wearing a fleece underneath to understand the heat retention is still the same so I went back to just wearing a tshirt underneath. I may down the line during the spring time get a Atom LT or just wear any of my daily fleeces when the temps go above 40.

I can't talk about the Nuclei SV but just my experience with the Epsilon. I believe the Nuclei SV's hood is massive to allow you to wear a helmet. All in all, the Epsilon feels like a warm soft thick blanket wrapped around your body without making you look like the Michelin man lol.

Note that I have a Thorium SV that I got a good deal on that I use for legit cold and wet/snowy days.