Chris Kinsey wrote a review of Big Agnes Hogan Park Sleeping Bag: 0 Degree Down on January 6, 2012
Hmmmm - NOW they change the name to Hogan Park. Mine says HOG Park on it. An unfortunate name but call it like it is. I am a BIG guy and I hate traditional mummies. The Hog/Hogan/whatever Park bag allows me to roll over, curl up in a fetal position, toss, turn, and stay comfortable and warm. I pair this bag with a 25x77 NeoAir (the bottom insulation in a Big Agnes comes from a pad - you must have a pad - and it's like being at the Hilton. The bag is well made. I have spent over 30 nights in it and have nothing to complain about. It is a 15 degree rated bag which I have used with the NeoAir down to 27 degrees. It was quite comfortable. I feel certain that if I wanted to zip up like you are supposed to and dress like you are supposed to the bag would be comfortable down to 15 degrees. Personally, I prefer to just avoid sub-freezing camping on a regular basis!
Downside - this ain't going to stuff into the sleeping bag compartment on most packs. Big is big. The synthetic fill compresses more than goose down, and is easier to dry out when damp, but this is still a big bag. It is going to end up on top of the pack, or under the pack. Which is great - because that allows my full size pillow and NeoAir to stuff into the sleeping bag compartment. Forget buying Big Agnes a bra (that's what they call it) and you will NEVER get it back in the original stuff bag. I use a Sea to Summit XL waterproof compression bag. With a little elbow grease it stuffs into that nicely, then you have just enough room to compress the air out and get three wraps on the top. You will need to give it some oomph to make this happen - but if you are a Hog/Hogan Park kind of camper you have plenty of oomph to spare - right?
Basic laws of physics - big and comfortable is not going to be small and light. But - if sleep ranks right up there with dry, fed, and happy on campouts - get the Big Agnes and be happy.