
NEMO
Disco 15 Series
Spacious for side sleepers; bulky, temp rating optimistic.

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The last bags we had were high end sea to summit that were rated to 0 to minus 15C. They were rubbish. We bought Neve gear quilts. Very light, compact and the best things ever. Much easier to get in and out of. We still use a liner/sheet sac. If you can afford to get them made, as opposed to off the rack, do that. Don't ever use your bags outside, especially next to a fire. Thats only for instagram pics. Pick a bright colour for the inside and a dark outside colour. We use trekology blow up mats. Exped deteriorate too easy. We use our gear a lot. Usually go for 1-4 months and sleep out 90% of the time.
I have a sea to summit backpacking bag that’s 15° rated and once it’s in a stuff sack it’s incredibly small for a 15°. Coleman is basically bottom of the barrel, sleepover style, when it comes to sleeping bags, I’m surprised you aren’t freezing to death at night.
At REI? Probably just the sea to Summit. Cottage brands just do a better job overall. Here's a good start, but there are tons of other options. https://www.garagegrowngear.com/collections/quilts-sleeping-bags?srsltid=AfmBOop9T_mFgmquiOSKZQgg1443MbZ_HlewD5AHWCbOT52ZRMPPJVRi
Knowing Kathmandu quality, this is likely as good as it gets with that bag. I wouldn't trust their temperature ratings. If possible, return it and buy a Sea to Summit or Mont or other brand sleeping bag. Sorry.
Never used a berghaus mate, snugpak is good for the price but I’ve upgraded to a sea to summit bag and a mountain equipment bag and can’t recommend either of them enough!
Quilts can get drafts, but then also sleeping bags compress and lose loft as you shift and expose the compressed side. About even in my experience. Sizing, quality of pad straps, or user error are all possibilities if you've had better luck with a bag over the quilt. Also, audio books with a sleep mask headset and ear plugs. Give a pillow a try as well. I use the better sea to summit version and it helped my sleep quality a lot.
End of reviews

NEMO
Disco 15 Series
Spacious for side sleepers; bulky, temp rating optimistic.
Hammock Gear
Classic Burrow 20°F
Budget king; very warm but heavier than ultralight.

NEMO
Disco 30
Spoon shape for side sleepers; prone to zipper issues.

Western Mountaineering
VersaLite
Durable, very warm; premium price, too hot in summer.

Katabatic Gear
Alsek 22°F Quilt
Versatile 3-season quilt; secure pad attachment, high price.

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NEMO - Disco 15 Series

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NEMO - Disco 15 Series

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NEMO - Disco 15 Series