I can't help but wonder if this is all a matter of technique. I work at an outdoor shop and I see more than a few people try to roll a bag and then cram the roll into the stuff sack. That would be the wrong approach, and when I show them that they can just stuff it in the STUFFsack in short order... Well, I get all sorts of different reactions.
From my experience with Marmot bags, it's a tight fit, but it's not that hard. You can also look into other stuff sack options, I use a Sea to Summit Dry Comp bag for my down filled back, and I can really compress it much better than just the stuff sack.
For starters, I'm a bigger guy, wide shoulders, overweight, the whole package, so usually I find mummy bags pretty claustrophobic, but the AlpinLite fits pretty well, it's not so tight that I can't move, but it's not so cavernous that it looses its function as a mummy bag.
I took this bag with me to the Grand Canyon in Nov '09, and while the night time temps dropped pretty low, down into the 40s or 30s, I was so toasty I had to open the bag up a little until fairly early in the morning. The weather was nice so I just set up on a picnic table and slept under the stars, no issues with condensation or anything.
I'm looking to do some winter camping next, I think due to the continuous baffles, I can probably shove some of the down from the bottom around to the top and maybe get a little extra loft, so we'll see how that goes.
The shank in these things is one of the most rigid I've come across so far. I work at a small local outfitter and I've seen my fair share of boots, and these things are rock solid. The soles are also very firm, one of the harder mixes of Vibram rubber.
They are a higher volume boot. Wider toe boxes than something like a Vasque that tends to taper in towards the end, and have greater volume at the midfoot. I'd suggest trying them before you buy them, although I do believe that they are available in narrow widths.