After the nuclear holocaust when the only living things left are Keith Richards and cockroaches, they'll be partying large in the Bibler Fitzroy tents that survived with them. We can attest to the bombproof design of the Fitzroy, a veteran of multiple Denali and Rainier attempts where it kept us safe and snug.
Like most tents rated for three people the Fitzroy holds two people comfortably and three in a pinch. A svelte seven pounds, the single-wall design and internal pole system set up quickly and securely in a storm. In a vicious wind you can crawl inside the tent to keep it from blowing away while you rig the internal poles; nice! The second door, extra room and more stable design give it the edge over Bibler's lighter and smaller Eldorado model in our humble opinion.
The clever side guy lines self-equalize, and when you fully stake this puppy out it is the most stable tent around. Like any single wall the Fitzroy is a compromise. The ToddTex fabric can build up some impressive frost in colder temps when you don't want to vent it too much, but that's hard to get away from with any single wall tent. The vestibule, footprint and gear loft are worthwhile additions. If survivability in a small package for two is what you're looking for, the Fitzroy should be at the top of your list.