Ok, I'm moving to Colorado later this year, and I'll need to upgrade my sleep system. As a rough estimate of needs, my research shows that the average nightly lows in Leadville (at just over 10,000 ft) are around 40F in July and August, and around 32F on either side of that in June and September.
I'm considering the JRB No Sniveller and Rocky Mountian Sniveller, or a Nunatak Arc Alpinist or Back Country Blanket.
No Sniveller, 2.5" loft, 21oz, $245
R-M Sniveller, 3.5" loft, 26oz, $275
Arc Alpinist, 2.5" loft, 20oz, $387
B-C Blanket, 2.5" loft, 22oz, $392
Some of my considerations:
1. I rather like the multi-use capabilities of the JRB contenders. I include the Down-To-Earth pad conversion in this assessment. Of course, the B-C Blanket gets multi-use points, too, with the velcro all along the edges, and ability to connect two together into a large 2P bag.
2. Do I need the 3.5" of loft if I want to use a quilt in shoulder season in the Rockies, or will 2.5" do? If so, should I scrap all these contenders and go with a more traditional bag with a draft tube/collar/hood, etc? But then again, see the Down-To-Earth pad conversion, above. (I know that temperature ratings are subjective, but I'm interested in people's experiences. I'm neither a particularly cold or warm sleeper.)
3. I'm a side sleeper and I move around a lot. In particular, I like to point my legs in different directions or keep one bent while the other is straight. As you can imagine, I find mummy bags uncomfortable. One plus for the B-C Blanket is that it is huge and looks like I can move around a lot in it. Heck they say it is "big enough for two", though I take that with a grain of salt. I can't seem to find dimensions for the JRB products. Are they big, too? Of note, they are square-cut rather than tapered, so they might also accomodate my kicking and rolling.
4. I'm not planning on camping on walls or other extreme mountaineering insanity, but I could conceivably be sleeping around 10,000 feet in the summer.
5. Sizing: I'm 5'10" and weigh anywhere from 185-200 lbs depending upon how the past few months have gone (currently around 195). Regardless of my nighttime gymnastics issues, I find the BPL/BMW UL 180 quilt to be too small for my shoulders- it is hard to keep it sealed under me to avoid drafts when it is particularly cold.
I have to admit, I'm looking hard at that Rocky Mountian Sniveller. With a hood attached and the Down-To-Earth pad it looks like it would handle pretty low temperatures. But do I really need that for anything less than camping on snow in winter? Will the 2.5" loft contenders handle the shoulder seasons?