I purchased this bag to accommodate two adult backpackers and one spoiled dog who likes to sleep under the covers. It's hard to see in the pictures, but the system includes a slipcover that couples the sleeping pads and the actual "bag" (more of a top quilt) that snaps onto the slipcover. As other reviews have suggested, it's not the warmest of systems and can be a bit drafty, so we usually pack an extra blanket. The bag is very lightweight and packs down smaller than my normal one-person sleeping bag.
When used with insulated pads like the ones from Nemo and the slip cover which snaps to the sleeping bag itself, this thing traps a lot of body heat. Especially if you are using it with another person which it is designed for. This system is cheaper and lighter than two individual bags of similar quality.
After spending multiple camping trips sleeping with my S.O. between two drafty, unzipped bags, it was time for an upgrade. Though I looked at a lot of options, I landed on the Tango Duo because of it's design, warmth rating and packability. Though it took me a long time to figure this out through internet research, the design of this bag is very unique. A separate slipcover (which you should definitely purchase if it's not included) fits over two sleeping pads to create one cohesive mattress. Then theres a hood piece that fits over the head of the sleeping pads. The hood then snaps to the top of the sleeping bag, which lays over and tucks under the foot of your sleeping pads. Though there's no bottom layer to the bag, the slipcover provides good insulation. Having just tested it out in 40-degree nighttime temps, I'm happy to report that it's exceptionally warm and comfortable. This thing gave me some of the best sleep of my life. Thanks to its 700-fill down stuffing, this thing is warm, but light and lofty. I also love the satin-y material. It also stuffs down super well - but note that you'll need to buy a separate compression sack. This bag couldn't be cozier. I highly recommend and can't wait to use it again soon.
We used this on the AT when it got down to 35 degrees. No problems. Actually it worked great. Light, warm, comfortable, and easy to set up. Not sure what else we would have needed or wanted.
Have used this for over 2 years. It's survived two-week trips to glacier, and yellow stone and over a dozen weekend trips. We love it.
I returned this immediately after I received it. A recent article in Sunset Magazine mentioned this sleeping bag with a double sleeping pad. It would not accommodate a double pad, only two single pads. Also, the slipcover is basically a fitted sheet that goes over your pad. The sleeping bag just goes over the top of the slipcover like a comforter, which accounts for how small and light the whole thing is.
Just got mine today and realized why it is so compact and light. It's not actually a sleeping bag but more of a blanket with slots to hold air mattress'. While we haven't used it yet, it's obvious that the sides will not hold in any heat. Basically I could have bought a rectangular bag for a fraction of the cost, cut off the zipper and used it as a blanket.