In reply to 0ni0n:
I've had a Montane Ground Control for a while which is good value as a packable extra warm layer which I've found good for throwing on for lunch on winter summits in fine weather. I'm not sure I'd want to sit in it for hours in foul weather. It doesn't have any big interior pockets to keep stuff like gloves/rock shoes in.
I got a Citadel a few months back for this winter, and it is an entirely different bit of kit. You feel like you're in a suit of armour and whatever the weather's doing outside ceases to matter, amazingly warm! A lot more spendy though, and doesn't pack down as small, (although it is pretty amazing the stuff sack it goes into). I'll be happy having it with me when on my own in the winter knowing if I get into trouble I can just hunker down in it and be safe while waiting for rescue.
The Fitzroy may be better value as you could use it for more all round purposes, packs down smaller, and is by all accounts still a very warm jacket.
I did find the Patagonia DAS a fair bit cheaper than the Citadel online but not anywhere I could try it on, and Patagonia stuff doesn't generally fit me as well as ME, so passed.
If you're skint, I'd probably keep an eye on the outdoor gear marketplaces and pick up the warmest jacket you can find and see how you go for a season, then can always shift it on and upgrade if you want something better.