Good tent but not best
I am accustomed to using single wall tents and it is necessary for me to open the vents as much as possible, leave wet clothing outside and control my body temperature. If I do that, the Firstlight seems to work fine for me. However it is a little short and the foot of my bag ends up wet. I carry a small bottom portion of a kitchen garbage bag to cover the foot of my bag and if it is cold, I use a waterproof (vapor barrier) inner bag to control my moisture.
A much better tent that I have used for 25 years now is the Stephenson Warmlight. It is longer, wider, ventilates much better, is more stormworthy, is about the same weight, and includes a vestibule.