Being a taller person (6'3") my choices in sleeping bag were quite limited. I bought this in the hope that I could get a noticeable improvement on my old Blacks 3 season bag, and what a difference it was! I can't say how this fares with the extreme cold but I've camped in 7 degrees and it has done me just fine. (I get cold very easily). With my previous cold weather bag I would have noticed the cold. The size and weight is a massive improvement over my synthetic bag and I'm tempted to even use it in summer when the time comes. The baffles and general features/fit are good too, although the zip has snagged on the shell fabric a few times it's not enough to change my general thought about this bag.
In terms of accessories it comes with a stuff sack with a floating lid type design (which I personally prefer) and a large mesh bag so that you can store it at home without compressing it's filling, which I think is a nice touch.
Overall I think it's a great bag and in the long term the cost will be covered by the additional warmth and weight gain over using my previous cheaper sleeping bag. Now what to do with the old one!