You'll never find a better deal on a sleeping bag of this caliber. Qualitywise it's a very high-end bag (incredibly light weight, 850 goose down, really well insulated, and they'll last forever). I took mine backpacking in Yosemite for a week, and it kept me very warm every night. When it gets too warm, I just zip it open a bit.
I got one for me and the 35-degree womens version for my wife. They're the last sleeping bags we'll ever have to buy, so it's very nice that we didn't have to spend $1000 to acquire them.
This review was written in the old system and had content requirements that are different than reviews written today.