Reilly wrote a review of Big Agnes Lost Ranger Sleeping Bag: 15F Down on May 1, 2018
Familiarity: I've put it through the wringer
I own 4 different bags for different seasons and uses, but lately, I've been finding myself pulling this bag more often than not. It's so roomy especially for a restless sleeper like myself.
In a traditional mummy, I often feel confined due to the narrow shoulder box. With the Lost Ranger, I can side sleep and move around all night without twisting up the bag. The sleeping pad sleeve also helps to keep this sleeping system anchored which prevents ending up at the bottom of the tent while on a grade.
The material is soft, the down lofts well (no cold pockets due to down clumping), and the temp limit is pretty much spot on. It's the perfect bag for those summer/fall alpine lake trips. I've also used it for a hut trip in January with no problems. The weight is probably on the heavier side if you're a gram counter. But honestly I don't even notice the additional 12 or so ounces of difference between it's more expensive competitors .
The only caveat that I can find is that the hood is somewhat awkward. I can never get it to cinch down and it just feels too big to be useful. That's not a huge deal for me, however, as I usually sleep with a beanie on colder nights.
Also you need to use a decent sleeping pad with this bag as there isn't any fill in the back of these bags. I use insulated pads year round (BA Q core which fits perfectly and Kylmit static v which is a tight fit but still works). I'm a fan of this because it takes down that would normally be useless crushed under your weight and moves it to the front part of the bag where it actually helps. This makes it warmer without adding more weight - pretty genius.
If you're looking for a go-to bag that will replace a lot of your specialized bags, this is it. Lots of tech and a decent price. Another awesome product from BA.