View Full Version : Marmot Ion vs Western Mountaineering Ultralite 20F bags

01-22-2017, 17:23
Does anyone know how the Marmot Ion and Western Mountaineering Ultralite sleeping bags compare? Both are rated to 20F and are advertised as 1lb 13oz, while the Marmot is down on top with synthetic on the bottom and the Western Mountaineering is all down. Marmot claims the synthetic is better than down on the bottom because it doesn't compress as much... The Marmot is also cheaper and significantly roomier in the hips and ankles according to the specs. Do these companies have similar temperature standards? Are they likely equally warm or equally durable?

01-22-2017, 17:38
I would rather have the all down bag. I use a quilt instead of a bag http://www.enlightenedequipment.com/


01-22-2017, 19:21
Disclaimer: I own 2 WM bags: Alpinlite and Antelope.
The Ultralite does not have a side block baffle. You can move the down a bit, to the top or bottom, for warm or cold seasons.
The Ultralite is a minimum inside dimensions mummy bag. After many years with a similar size bag I moved to the roomy Alpinlite.
The Versalite is a 10 degree bag and the internal dimensions are approximately in between the Ultralite and Alpinlite. At 5'-8" and 145 pounds, I find the dimensions of the Versalite/Antelope perfect.
The EN Lower Limit rating of the Alpinlite is 16 degrees. I just recently slept in mine on the Xtherm Large at 12 degrees. I would expect the Ultralite to do the same.
If you are a cold sleeper, give some thought to the Versalite.
Good luck.

Sent from my iPhone using Tapatalk

01-22-2017, 19:35
Personal Preference opinion of the Ion:
Fitted hood that doesn't open relatively flat. Minus.
Lack of draft collar. Minus.
Treated down. Minus.
13.5 ounces down vs. 16 ounces in Ultralite. Minus.
4.75" loft Ion vs. 5.5" loft Ultralite. Minus.
The interior dimensions are too close to make a real difference unless you are a large person in which case you need a different bag.

Sent from my iPhone using Tapatalk

01-22-2017, 20:46
That ion does have an EN comfort rating of 28.4f, which is pretty good. The wm ultralite bag might be a few F warmer than that
The down fill specs might be hard to compare because of the synethic bottom on the ion

01-23-2017, 09:59
Really comes down to what is more important to you. The Ion can be had off Massdrop currently: https://www.massdrop.com/buy/marmot-down-synth-bags

For $250, I would probably take the Ion. YMMV

Rex Clifton
01-23-2017, 17:35
For me there is one hard and fast rule, nothing beats Western Mountaineering sleeping bags. The question really is, do you have the $$$?

Sent from my Nexus 6P using Tapatalk

01-23-2017, 22:01
For $250 dollars it would be worth a few nights in my backyard at and below 20 degrees. Or one night if I was cold before the temperature dropped below freezing.

Sent from my iPhone using Tapatalk