I bought the previous year's bag in this model (ascent 700, 2011), but it's much the same design with a (slightly) different fabric.
I've camped in this bag perhaps 100 nights in the last year, open in the summer and in autumn, and fully zipped up and hooded in the winter.
I have some criticisms: Firstly, the temperature rating on mine is dubious - it is warm enough in places, but I felt certain repetitive 'cold spots' at just above freezing temperatures. Are there patches with less/no down? I tried to move it around, with the same 'drafts' in those places. I've used bags with similar or less-warm temperature ratings that I feel are warmer than this one, irregardless of my being a 'hot' or 'cold' sleeper, and what meals were eaten before sleep, and so on.
I'm not so sure about the heat distribution. my hooded head was overly warm, whilst I felt the cold around my legs at times, and so modulating temperature can be an issue - one you have to manage using the draft-stop I guess.
My bag leaks a lot of down (more than any other down bag I've owned), especially from the seams, and especially around the foot-box. This is disappointing, less because I think the bag will run out of down, and more because I'm constantly having to clean out tent, socks, leggings, gear and bags etc because of the down spreading. Yes, down bags can and do leak a little down, and perhaps this issue explains the change of fabric on the newer version.
When I bought the bag I was told the fabric was very water-resistant, but this is also highly questionable, and I would not rely on it to stay dry in damp or wet conditions. (I feel more confident in my Mountain hardwear bag.) Any beaded water will eventually soak in if it doesn't run off, I believe.
Perhaps I've had bad luck with these issues, and I mention them only so that the buyer can beware.
In other areas the bag is quite good:
The inner fabric is very light and comfortable, silky on the skin. I've used it in sub-zero temperatures, but am always careful to wear thermals in colder climbs (I'm fairly confident in it, but not 100% convinced, as I am with my similarly rated M.H. bag).
The drawstrings worked well enough around the hood, and draft-stop, but were very long once pulled tight and were sometimes a nuisance.
The stuff sack is good, strong, and reduces the bag to a good size.
On the whole, it's well thought out and a comfortable bag, but it could do with some tweaking - perhaps these issues have been dealt with on the 2012 and later models.
On sale, it was a good deal, I think.