It's rated to 15 degrees. It has built-in pillow pockets to hold your folded fleece jacket as an ad hoc headrest. There's a zipper on each side, allowing easy access for both sleepers to get in and out at night.
But what seals the deal is Big Agnes' signature pad sleeve, a large pocket that is custom sewn into the underside of the bag to accommodate a sleeping pad. Slip a pad inside and it's held tightly in place, becoming one with the big puffy bag. You can't slip off or roll over the edge.
The effect with the pad in place and the sleeping bag cozy over the top creates a cushy platform akin to a queen-size bed.
Big Agnes (www.bigagnes.com) recommends its inflatable Hinman pad to mate with the Dream Island. The Hinman, which costs $140, measures 50 by 78 inches at 2.5 inches thick.
Add the $239 bag and with tax and shipping your dream sleep system is running upwards of $400.
Is it worth the cash? For the consummate car camper, maybe. If you're the type who totes along a portable espresso maker, Lexan wine glasses, leg-rest-equipped camp chairs, and solar showers, then the Big Agnes setup might be up your alley.
Beyond the high price, other cons include the bag and pad's size and weight: Each one weighs more than 9 pounds. They don't pack up small either, each requiring significant trunk real estate in my stationwagon.
The gargantuan size of these products limits them solely to car camping. I wouldn't even try to take them on an overnight canoe trip, for example.
One last point, and this is speculation: Though I tested the bag in temps of about 40 degrees, I would be amazed if the Dream Island was faithful to its 15-degree rating. My wife and I were cozy on a cool autumn night. But had the temp plunged that far below freezing I'm not sure the Dream Island would have been adequate.
All that said, price and portability aside, if you want the ultimate in the wild sleep system--the simulacrum of a mattress and quilt in your tent--then this might just be your bed.
Stephen Regenold writes The Gear Junkie column for eight U.S. newspapers; visit www.thegearjunkie.com for video gear reviews, a daily blog and an archive of Regenold's work.