I felt a bit apprehensive before purchasing the Plasma 30 bag. It’s purpose seemed really narrow: Hikes where the temperature might be in the upper 60s and where the nights could plunge to around freezing, an alpine bag for early spring and late fall.
When I hiked to Discovery Point in Crater Lake National Park, I was glad I had this ultralight and warm, down bag. The temperature was around 32 degrees, and I needed no more than my long-underwear and baselayer to keep warm. I took advantage of such well thought out and luxurious features as the draft collar, and hood. At 32 degrees I was very warm.
At 1.44 pounds this is also the lightest 3 season bag I’ve ever used. In off-season Alpine hikes, I’m very confident this is the bag to use.
For winter, I would use the Lamina Z Torch sleeping bag which weighs 3.94 pounds. It’s rated to 5 degrees Fahrenheit, and kept me very warm during New Year’s Eve in Yosemite when it was around 9 degrees.
Should you buy a Marmot Plasma 30 Bag? I think it’s the sort of bag for ultralight-backpacking from Spring to Fall.