Yeah, I came of age doing winter trips in the Presidentials and ADK in the 1970’s, before I moved West. I got a NF Ibex bag in 1976, which was the state of the art in that era for a -15* bag. My first week long trip saw temps -15/-20* at night, no higher than zero during the day. I lost insulation rapidly and by day five had essentially a +15 bag. By 1978 I switched to a synthetic bag rated to -20* and never had an issue. Later in the early 80’s I switched back to a down USA made Marmot w/ Goretex shell, and that’s when I went to a VBL. But that early trip of losing loft seared in my consciousness the need for a VBL, and I’d never contemplate an extended winter trip without one. But I’ve never been a “heavy sweater”, and will only use the VBL with capilene-type synthetIcs on... I don’t find VBL’s obnoxious, but everyone’s experience is uniquely their own.
