The MSR Nook performed well while at the Rab Mountain Marathon. It has adequate space for two (6ft+ men) especially when you take into account that it has such a small pack size - we managed to fit it in to an Inov8 Race Elite 24 pack along with the rest of our race kit. The Nook can be easily erected with no hassle; the inner is pitched first and then the outer fixed on top. We had excellent weather for the end of September but if it was raining you wouldn't end up with a very wet tent whilst putting it up due to the speed of which the Nook can be erected.
The fly pitches quite high, which leaves a gap between the flysheet and ground sheet. This may have been the reason why we were quite cold on the first night but this is great for ventilation. On the first night camping at the Rab Mountain Marathon (bearing in mind that it was the end of September) we didn't use the guylines in the middle of the tent, which may have been the reason why there was some condensation inside. However, on the second night we did use those guylines and there was no condensation when we woke up on the Sunday morning. It is difficult to tell whether this is the reason, as the second night was slightly drier but I would recommend using these guy points.
The MSR Nook is slightly heavier than some 2 man tents, but this does not affect pack size and the extra room is definitely worth the extra grams. However, an attachment for the inner to the fly could allow for even more room inside but this would add some extra weight. Overall, a superb tent from MSR, which seems to pack in to nothing for the amount of space it offers.