I like the Heater Body Suit when it's bone chilling cold.. Quiet, hides all your 'fidgets' and easy to regulate by just opening the zipper
Additionally I'm not walking or climbing into my stand in anything super warm, so I have to try and get heavy bibs over my boots, a jacket under my harness, etc.. With the HBS I just step into it and pull it up, I don't have to cinch it down right away since I'm still going to be warm from the walk in but it's quick to cover up when I'm ready