If you own only one jacket, this should be the one you buy. I own the "windshirt" version of this jacket. I summited The Grand with it as well as Baxter's Pinnacle. I climb/hike hard; and I sweat a lot. And the awesome thing about these jackets is that no matter how much you sweat, you never feel wet. NEVER. It maintains a very even temp as long as you keep moving. What's weird is that it insulates like a 200 or 300 weight fleece because it is windproof and the dual fabric layers creates a loft effect that keeps your temp even. The driclime fabric pulls the moisture out and to the outer layer, which then evaporates the extra moisture. The issue I have with the windshirt is no drawcord at the waist and collar...which this jacket version addresses perfectly. I have been skiing with it the last week and unless the weather is really cold (like 15 degrees or colder with snow and wind), you don't need a shell. A base and a mid layer with this jacket is a really balanced system. It's really great for touring/cross country skiing or any other high aerobic sport. Can't say enough good things about this piece. I treat it like a mid-weight fleece...that's truly windproof. Cool part is it packs down to a grapefruit and is half the weight of a similarly effective fleece. I plan to us it to do the Haute Route this April. I use a Craft zip-T base, a Patagonia R1 Hoody, then the Marmot DriClime Jacket over the top. If the weather gets bad, I will add an Arc'Teryx Alpha SV over all that. If we get stuck in REALLY bad weather, I have a Mont-Bell Alpine Down Jacket to save my butt. Hope this helps...good luck!!!