One Person Tents are great if you will be roughing it alone or in a group of individuals. But should you choose a bivy sack or a single person tent? I will review a lightweight tent and a bivy to see what the differences are.
MSR Skinny One
The ultra light 1 person tent that stand out to me is the MSR Skinny One. It is ultra light weighting at at 3 lbs (l.36kg). Even though it is light it is still a very weatherproof tent. It is rather spacious for a single tent with the shelter being 36.5 cubic feet. It has a roomy vestibule allowing you to store your pack and boots outside the tent. The ventilation is superb with mesh windows providing excellent airflow. The set up is easy and fast. So overall it has many things going for it.
Outdoor Research Alpine Bivy
The Outdoor Research Shelter is quite popular as it has twooles to create an adjustable awning which keeps the sack off your face while sleeping making the bivy less claustrophobic! This shellter weights in at 2 pounds (0.91 kg) so it is fairly light. It is suitable for four seasons and its very waterproof. The size is 84L x 26 Shoulder x 19 (foot) inches. The fabric is 3 layer gore-tex nylon. It has mesh netting; so on the clear nights you can leave the main zip open and gaze at the stars without worrying about bugs. It has good ventilation but it is recommended to leave the zip open and inch or two. It also packs up small making it easy to carry.
So the main difference between the 1 person tent and the bivy are:
Weight: The bivy weighs in at a pound lighter than the MSR Skinny
Space: The MSR Skinny has a lot more space.
So it all depends how conscious you are of your weight, how much time you will be spending in your tent. Some people just like more space in which case the tent will be better. If you are going on a long hike an extra pound might make a huge difference. So think about what you need your shelter for and then make your decision.