We've used the Jack Wolfskin Worlds End tunnel tent for several years now (details on our site below) and are very happy with it. We will be getting the Jack Wolfskin Tundra III soon for this years tours. You are right about having extra space for cooking in and not feeling crowded in spending days in one during bad weather. They are heavy, our old tent is nearly 6kgs the new one will be nearly 5kgs but do not wory about the weight so much, you get used to it after a few days. Just think of those world travelers going over the Himalayas and the Andes carrying several days of food and water
We believe comfort should come first.
I should mention that we almost always go to organized campings or get a room when we have enough of bad weather.
We've looked at the Hilleberg Nallo but the price just put us off. That is just too much money for a tent and the material is almost see through. We would consider one if going for year or longer tour, a lot of people (world travelers) swear by them.
If you got the money though you can also check out the Hellsport collection (Fjellheimen X-Trem 2 Camp) just as good as the Hilleberg if not beter.