First of all, I have to say that this as a great bag! I've had it for over a year and used all across the US and in all conditions and temperatures on all sorts of adventures, so I feel that I can speak to it well.
It is a decently warm bag, although I find that it may be rated a little colder than is realistic, but not by much if so. Granted I sleep colder than most, but I took that into consideration. The material is good and handles moisture well and the zippers don't have too many issues. The zipper air guard does occasional get caught, but not enough to complain. One thing I have noticed and wish I paid more attention to before buying the bag is that it is a very big fit when it comes to a mummy bag. So unless you want the wiggle-room, I'd find something that fits more narrowly and is thus more heat efficient. In the future I will be paying more attention to this and will even be considering it as I plan on upgrading soon.
I will say that I'm not a big fan of the drawcord, because it's difficult to work once already zipped up in the sleeping bag. The mechanism is stiff and the drawcord is tough to handle. Maybe I just have issues (and that is always a possibility with me), but it seems more difficult than it needs to be. Also, the small pouch on the outside of the bag for cellphones or batteries causes me disappointment. Because it's on the outside of the bag and thus the outside of the insulation, it doesn't keep things warm. So, if I were to use it for batteries or phone, my power levels will all be zapped by morning time.
Furthermore, I don't feel that it is as compressible and light as they make it seem when advertised. For someone like me who does mostly backpacking and hiking, I need something more compressible and more lightweight and this is the reason I'll soon be upgrading to a quality down bag like either Feathered Friends or Western Mountaineering (I haven't decided yet).
If it's helpful, I also have this video review on my youtube channel: