I absolutely love this bag. I've had it for roughly a year and a half now and I wanted to hold off on reviewing it until I've really drug through the mud. I've used this trekking in the Grand Canyon for 5 days, climbing three 14ers in summer and winter, and backpacking twice with it when it has rained nonstop for more than three days.This bag has never failed me. It has gotten wet twice, once in Guadalupe Mountains National Park during a freak thunderstorm and again on Mt Massive during a rainy spell that lasted all night. I have never felt wet inside the bag nor has it affected its ability to keep me warm.This is also the warmest bag I've ever been in. It is definitely a 20 degree bag. I brought it to Estes Park this winter with a bag liner hoping that it could handle temperatures right above zero. It did great in the teens all night until the wind started picking up and blew all my insulation out of my bag. I never got extremely cold, mind you, but I was cold enough to wake up. Thats not so much a critique because this bag performed above and beyond what it was advertised to do.As far as weight, this is the lightest most compressible bag I've ever owned. Friends I go backpacking with are always amazed at how lightweight it is. I let a friend of mine borrow this bag while I slept in my fiancee's bag in another tent, and the next morning he could not stop talking about how warm and comfortable he was because it felt like a thing blanket.The only reason I gave it four stars is the price. A nearly $500 bag just isn't competitive when there are just as good bags for $200 or less. If I had to go back and make a different decision, I would have bought the zero degree bag instead.I HAVE to mention that EB sleeping bags are incredible pieces of engineering. I expect this bag to last me years, maybe even a decade or two. My grandfather still has his sleeping back from EB that he bought in 1979, and I used it for years before I bought this bag in 2016. Worth it.