Josh K.wrote a review of Marmot Plasma 15 Sleeping Bag: 15F Down on October 4, 2015
Familiarity: I returned this product before using it
The Plasma 15 is by no means a bad bag, but it's shocking anybody would pay nearly $700 full retail for this thing. I got mine on sale for $430 and am still sending it back. Why? Because you can do a lot better in this weight range.
I compared it to two other bags: The WM Versalite and the Feathered Friends Lark. Both of these bags are rated 10 degrees, but all 3 bags feature about the same amount of down fill, so I think they are very comparable. The WM uses 850, the Marmot 875, and the FF 900. Trust in those numbers as you see fit.
I weighed all 3 bags. The Marmot came out just above 2lbs, which was about 1/2 oz more than promised. the WM bag came out at 2lbs 1oz, or 1oz more than stated. The FF bag actually came out just a bit less than the 2 lbs stated, at 1lb 15.5oz. So all and all, the bags are nearly identical in weight and stated amount of fill.
Laying the bags out next to each other is where the difference is obvious. The Marmot just looks sad next to the WM and the FF. Again, it's a nice bag, but it's clear it isn't in the same class as the other two. They are all cut a bit different, so individual taste will vary, but all fit well enough for me.
The fabric on the Marmot is really nice. It's much quieter than the other two bags and quite comfortable. The WM fabric is nice enough, but nothing about it stands out. The Pertex Endurance UL used on the FF is definitely the noisiest of the bunch. This may bother some people. It's very light, however, and claimed to be very water resistant.
One other thing the Marmot has that the other two doesn't is DWR coated down. Maybe this is important to some people, but I have had a problem with soaked down exactly once in 20 years, so frankly I believe keeping a down bag dry is more about the user than fancy down coatings. It also features the vertical baffles, and I'll leave it as a user exercise to figure out how much difference they make. Reading about them at the insotech website they seem very much like a gimmick, and holding the bag up to light showed a huge amount of uneven down distribution. Some areas looked to have almost no down at all. I'm not convinced the vertical baffling is a good idea.
Granted, I did not use this bag outside, because I had to keep the bags unused to be able to compare 3 of them within my house. So you can take my review with a grain of salt. I have no doubt it will be a comfortable and warm high quality bag. I give it 3 stars because I am 100% convinced that you can get a better bag for far less money. How Marmot thinks they can charge nearly $700 for this bag when you can get a USA made FF or WM bag for so much less is beyond me.
In the end I decided on the FF Lark, and will be sending the WM and Marmot bags back, even though the Marmot would cost me $150 less at the sale price I found it.