Sea to Summit Traverse XT II

Brilliant technical features that just work. If you look at the manufacturer's specs, you can see that this bag is, in its class, just about the most technically advanced bag in the world. I tried mine out last weekend and the expectations were completely met with perfect build quality.

The hood worked well. The lofting was excellent. I have owned four bags for different temps and conditions. I should have just bought this one bag. You can snug it up for snow and cold. You can partially unzip the sides for warmer temps.

You can also totally unzip the side and the foot region to turn it into 2 dooners. The back and the front have different thicknesses of down so you get a choice of 2 dooners.

The outer has hydrophobic nano particles to act  as permanent water repellants. Inside the first layer you have layer of synthetic down so if any water gets in it will still not affect the insulation very much.

Then inside a second layer you have treated goose down with 850 loft. This treated down works better than natural down in wet conditions — it too is treated. So you have three levels of water protection, which is great for me since my previous bags had none!

This bag was not sweaty at all — a common problem with waterproof bags. In fact it was less sweaty than a bag without any waterproofing but with the same temperature rating.

Overall: Probably the best bag in its class in the world: Highly, highly recommended. Hence 5 stars!

Update May 2015:

Just back from a second trip. The bag stayed warm and dry. It was not clammy or sweaty, just nice. This time I teamed it up with a Sea to Summit Comfort Light Insulated pump-up mattress. The pump is a Sea to Summit Jet Stream Pump Sack and also works with the Sea to Summit Aeros inflatable pillow.

The whole system worked like a dream. Best night's sleep I think I have ever had (in 30 years). Temp in the morning was around -10°C.