Just got back from a very cold winter outing. The carbon fiber poles handle the cold well - my buddy had to use his stove to warm up his AL poles before taking them apart. I also used a silver reflective emergency blanket between the tent and the rainfly to keep the inside a little more toasty. My only gripe about the tent is that it is difficult to ventilate if it is raining. MSR recommends opening the door from the top and placing the pole shim in the opening to help ventilate, but that doesn't help if it is raining. I haven't tried it yet, but I considered, after the fact, staking out each door individually so that the doors overlap for rain protection but don't zip (allowing more ventilation).
For me, 5'10" 200lbs, this tent is a very roomy one person tent, but it would be very uncomfortable to have anyone else but my wife in the tent with me. The weight allows me to carry all the tent materials without feeling like I took too much stuff. It also packs small enough that I can stow it in the hatch of my Carolina 12 kayak and have PLENTY of room for sleeping bag, food, stove, booze, etc. all in the same hatch. It comes with good stakes etc, but I got some extra stakes and glow cord to really tack it down in case of high winds.
Definitely go with the 2012 version with the two doors - in the 2011 version, the opening to access your rear vestibule from inside the tent, is just poorly designed. -The vertical zipper barely allows anything but your fist to pass through. Otherwise, this is a fantastic tent!
Oh also, my cross pole (on the 2011 version) snapped square in the middle (the contact point with the main(long) pole)! MSR replaced it at no cost and explained that the replacement (native to the 2012 version and later) has a slight curve in the middle section to allow for more flex against the downward tension on it.