I did a quick search on these and didn't find anything other than two gear swap posts, so here goes.

Just a few minutes ago I was looking through STP as they have a 40% off coupon going on, and I stumbled on this:

http://www.sierratradingpost.com/mountain-hardwear-35and50-f-down-flip-sleeping-bag-600-fill-power-semi-rectangular~p~5501g/?filterString=sleeping-bags~d~208%2F&colorFamily=01

It's a down sleeping bag by Mountain Hardwear, semi-rectangular cut that can be unzipped all the way to a quilt, weighs 1 lb 13 oz, and costs under $160. The part that really caught my attention, however, is the "switch" feature from which it gets its name. The sleeping bag has different loft heights on the "bottom" and "top" which can be switched (i.e. you just flip the sleeping bag upside down) in order to warm up (35-degree side) or cool down (50-degree side).

Personally, I think this is an excellent idea, especially coming from a such a large brand that generally doesn't cater to ultralighters. Of course it will never be as light or flexible as a simple quilt, but I can see a lot of benefits to having a bag like this if you're not quite ready to make the switch to quilts. It provides the ability to adjust to the temperature simply by flipping the bag over, and you can unzip the bag all the way and use it as a quilt or even share it with your significant other. It also caters to those who dislike the cramped nature of mummy bags.

Have any of you guys ever used something like this? What are you thoughts?


Also, in the middle of writing this I added it to my cart to see what the total was with the discount and it ended up being just barely over $100, so I bought it and am going to try it out.

Edited by nsiderbam on 02/27/2013 17:21:25 MST.

George

I bought one yesterday for $136. Seems quite nice. I like the zipper system that allows for foot venting. Weighed in a bit less than #1-13 with stuffsack. Compressed to about 6x11.

I plan on using it with a Borah bivy. I'm a warm sleeper, so I think I can be good to the mid 20's wearing a moderate amount of clothes. I going to sleep out in the garage tonight for a test. Would rather sleep outside, but I don't want the neighbors thinking there's a dead body in the yard. ;)

Dean

This looks a lot like my old Marmot Grouse: semi-rectangular and opens flat to allow zipping to a bottom sheet to make a two-person bag.

But in the Grouse the baffle between the top and bottom (running the length of the side) is NOT sewn closed on the inside. By shaking the bag from one side you can cause down to migrate from that side to the other. In principle you can cause any amount of down to move, so one side could have almost all the down, the other almost none. I haven't tested the full range, probably the internal construction limits how much loft can be achieved on the full side.

And down doesn't seem to move unless you work at it. Normally I keep it at 50/50 for two persons, but it was useful to move more down to one side for single person use.

Continuous baffles in a bag achieve this too. Just shake the down to the side you'll be laying on top of.
(Edit: Woops, Elliott already mentioned it)

Also, check out Sierra Designs Pyro Manic 15/30
Its a 30* down bag that you can add a sort of a torso
blanket panel to the inside to make it a 15* bag.
You can carry less weight in summer, then just add
the extra down panel in the winter for more warmth.

It's actually really cool. There's video showing how it works.
Usually pretty expensive, but I've seen it for well under 200 on SAC from time to time.

Edited by LunchANDYnner on 03/21/2013 11:20:21 MDT.