Hands-on Gear Review

Marmot Plasma 15 Review

Marmot Plasma 15
By: Chris McNamara and Max Neale  ⋅  Nov 13, 2012
Price:  $679 List
Pros:  900-fill down, ultralight shell material, comfortable hood and foot box, lightweight.
Cons:  Cut wide in upper body = comfy but less thermally efficient, only two sizes, expensive for its weight/warmth.
Manufacturer:   Marmot
  • Warmth - 23% 8
  • Weight - 22% 6
  • Comfort - 25% 8
  • Packed Size - 5% 6
  • Features - 10% 6
  • Versatility - 15% 4
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Our Verdict

Product Discontinued
While this product is discontinued, we have an updated Backpacking Sleeping Bag review to guide you to the best match for you among today's top models.

The Marmot Plasma 15 is a luxuriously comfortable, sleek, high-performance sleeping bag fashioned with 900-fill goose down and ultralight Pertex Quantum shell material. Vertical baffles, a large toe box, and a well-designed hood make the Plasma one of the most comfortable three-season bags we've ever tested. But the bag comes up short in terms of its warmth to weight ratio and versatility.

Our Analysis and Test Results




The Marmot Plasma 15 is a skillful combination of performance and comfort. The bag is stuffed with 17.6 ounces of 900-fill down- the best money can buy. Its shell material is the hyperlite yet surprisingly durable 10-Denier Pertex Quantum. What sets the Plasma apart from most other sleeping bags, however, is its vertical baffles, which conform to your body and make for a blissfully comfortable nights sleep.

Wade Woodfill, the Plasma's lead designer, did an exceptional job at making the bag very comfortable. Vertical baffles are the primary reason for this, but the bag's generous cut (which fits both men and women well), an expansive foot box, the silky smooth fabric, and a well designed hood area contribute, too. The bag's neck baffle is the second most comfortable out of the fourteen three-season bags we've tested. It closes around your neck without fuss and secures with two snaps, which provide an easier, more comfortable, and more secure closure than the velcro found on most other bags. The design of the hood, too, prioritized comfort. A small tube of down buffers the drawcord so that the hood remains comfortable even when the cord is fully cinched. (The Mountain Hardwear Phantom and the Sierra Designs Cloud 15 are only other three-season down bags that do this as effectively.) There's also a mini down pillow sewn into the hood. These factors make for a splendidly comfortable sleeping experience.

While the Plasma is very comfortable, so, too, is it lightweight. A regular size Plasma 15 weighs thirty ounces, which places the bag among the lighter bags we've reviewed in this category.


With the Plasma you're paying a lot of money for features that make the bag more comfortable. The problem is we rarely find sleeping bags to be uncomfortable. Our numerical ratings prioritize weight, warmth, and versatility more than comfort, which is more in line with most backpackers' needs. The Plasma could be a good option if you want the most comfortable sleeping bag, can afford to carry the extra weight, and pay the price premium.

The Marmot Plasma 15's luxurious interior. Note the full down collar and the overfilled pillow! These features make the bag slightly more comfortable and add weight. Hoodless bags solve the draft collar problem by cinching at the neck.
The Marmot Plasma 15's luxurious interior. Note the full down collar and the overfilled pillow! These features make the bag slightly more comfortable and add weight. Hoodless bags solve the draft collar problem by cinching at the neck.
Like any other article of clothing, it's best to have a sleeping bag that fits you well. A bag that is too large will result in drafty dead air space. One that is too small or too tight will not allow down to loft properly. The highest performance sleeping bag will strike a happy medium between the two; you'll be plenty comfortable without having too much extra space. Unfortunately, the Plasma is only available in one cut and two lengths (Regular and Long). Most other companies, even Mountain Hardwear, offer their popular bags in a Women's cut, which is wider at hips and narrower at the shoulders. Some companies, such as Western Mountaineering, offer their bags in three different lengths including a Short that fits people up to 5' 6". Furthermore, Feathered Friends offers four different cuts of their popular three-season bags. This allows you to get a bag that fits as close to perfect as possible. The Plasma is designed to fit men, women, skinny people, average people, and wider people all at the same time. This negatively impacts performance because the bag fits very few people perfectly. For example, the Plasma is cut to accommodate women's wide hips and men's wide shoulders at the same time. If you have one but not the other you'll find part of the bag to be inefficient, possibly creating draft dead air space. If you have neither wide hips nor wide shoulders or are shorter than 5' 10" you'll find the bag to be too wide or too long. Fit is an important point to consider when looking for a top-of-the-line sleeping bag.

The Marmot Plasma at left has a vertical baffles  a wide cut  and large toe box. The Feathered Friends Hummingbird at right has continuous horizontal baffles (more versatile) and is available in 4 cuts that maximize thermal efficiency and reduce weight.
The Marmot Plasma at left has a vertical baffles, a wide cut, and large toe box. The Feathered Friends Hummingbird at right has continuous horizontal baffles (more versatile) and is available in 4 cuts that maximize thermal efficiency and reduce weight.
The Plasma 15 has several other inefficiencies that reduce its performance. Although vertical baffles are slightly more comfortable, it's well known that continuous horizontal baffles are the most versatile for three-season use. Other top manufactures, such as Western Mountaineering, Feathered Friends, Katabatic Gear etc., use continuous horizontal baffles, which are better because they allow you to adjust the down to the conditions at hand. If it's 60 degrees when you start climbing a mountain and zero near the top you can move the down to the bottom when it's warmer and to the top when it's colder. Down provides little to no insulation value when it's compressed. So why sleep on it? (Other bags, such as quilts made by Katabatic Gear, take this line of thought further by eliminating the bottom of the bag all-together.)

The Plasma's features Flow Gates, a proprietary technology from Insotect, that divides each baffle into seven or eight sections (says Marmot's Jordan Campbell) that stabilize the down so that it doesn't all end up at your feet. Supposedly, you're able to move the down between Flow Gates, but we've found that to be quite difficult, and we don't see any sizeable advantage of being able to move down between gates (unless your feet are especially cold). Thus, the Plasma's vertical baffles and Flow Gates are less versatile than continuous horizontal baffles found on most other high performance three-season bags. They are, however, more comfortable.

On a less critical note, the Plasma comes with a black mesh storage sack. Our testers much prefer solid cotton storage sacks because they keep the bag much cleaner.


Finally, the Plasma 15 retails for a whopping $470. The bag has many well-designed features, is very comfortable, looks attractive, and performs very well. The Plasma 15 the best all-purpose lightweight luxurious bag that can be purchased easily and tried on in major retailers across the country. It's not, however, the best value. The Mountain Hardwear Phantom 15 weighs an ounce less, is nearly as comfortable, and is much cheaper. This is the Ferrari of sleeping bags.

Front to back: Valandre Bloody Mary  Feathered Friends Hummingbird  Katabatic Gear Sawatch  Sierra Designs Vapor 15  Feathered Friends Hummingbird  Marmot Plasma 15  and Sierra Designs Cloud 15. Note the different cuts and hood designs.
Front to back: Valandre Bloody Mary, Feathered Friends Hummingbird, Katabatic Gear Sawatch, Sierra Designs Vapor 15, Feathered Friends Hummingbird, Marmot Plasma 15, and Sierra Designs Cloud 15. Note the different cuts and hood designs.

Chris McNamara and Max Neale

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OutdoorGearLab Member Reviews

Most recent review: July 19, 2015
Summary of All Ratings

OutdoorGearLab Editors' Rating:  
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Average Customer Rating:  
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100% of 1 reviewers recommend it
Rating Distribution
2 Total Ratings
5 star: 50%  (1)
4 star: 50%  (1)
3 star: 0%  (0)
2 star: 0%  (0)
1 star: 0%  (0)

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   Jul 19, 2015 - 01:20pm
Rozsha · Backpacker · MN

Am a middle aged, 6' tall, 185 lb. woman with a thyroid autoimmune disorder who tends to sleep cold, toss and turn, & side sleep. Comfortable sleep isn't only a necessity, it is vital for my health.

I have used the Plasma 15 in night temperatures ranging from 15-65 degrees F, dry to moderately damp, and because of its unique cut & full length 2 way zipper, I managed various adaptations/configurations to keep me comfortable and well rested. I always wear some type/weight of socks, wool or silk clothes, and knit cap to keep the bag clean. Hood and synch cording is both effective & comfortable. Foot box insulation for warmth is superlative. As I turn from side to side on a cold night, the relofting of the down on my newly exposed side is quick. (Used in combination with an Exped Synmat 7 UL XL in spring/summer/fall and Exped Downmat 9 XL in low elevation, moderate winter.)

I paid the extra money for the high quality fill and shell in order to keep the weight/volume as ultralight as possible while maximizing comfort for health maintenance. Feather loss is next to non existent. I will never need another sleeping bag for 3+ season, any elevation, back country camping until this one wears out.

I have yet to double the Plasma 15, like I did my Marmot Helium, similar rating, with a light weight synthetic summer bag over the down bag in colder temperatures. The Plasma 15, with heavy wool long underwear has kept me comfortable down to 15 degrees F. I assume a light synthetic bag over the Plasma 15 could get me closer to 0 degrees.

Bottom Line: Yes, I would recommend this product to a friend.

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