Slept in one for a week.
Slept in it on nights ranging from 10 to 17 degrees. We did not encounter particularly high winds but it snowed for around 72 hours with a maximum of around 10 inches during any one sleep period.
I did not find the condensation issues to be any different from a tent/fly setup.
There is no getting around the humid air freezing to the tent walls but with all the vents open it was as good as I've experienced in any tent. If we closed the mesh on the vents it was significantly worse.
We did not cook in the tent. The snow sweeping opening in the floor is a nice touch for getting rid of snow tracked in or frost knocked off the inside tent walls.
The "vestibule" is very small, there was room for one of our packs and my boots.
There were 2 of us in it and I can't imagine having to share it with 3. There was just enough room for our 20" wide sleeping pads and to wedge a few things between us and the tent walls.
Overall, a good winter tent for two but I wouldn't try and sleep 3 unless you're using it in comfortable weather.