I climb, I mountaineer, I run around in portland weather, I will wear this jacket for the next 3 years. Should I get this, the MX Gamma Hooded, or the Elipson hooded thing? Also, how the hell can I tell the difference between all of the Arcteryx lT and MX and SA and BR and PP and ??'s out there?

Well it depends on what your looking for when it comes to weight and protection levels. The Epsilon SV is on a bonded poly fabric and is only 16 oz. so its a lighter weight jacket. And no Gore-Tex or Windstopper. But it is highly breathable and will shed light rain and is wind resistant, but not proof. The Gamma MX hoody is a Polartec Powershield softshell which is good for many different types of weather conditions, hints the MX (mixed) rating it gets, but it too is lighter than Sigma SV at 20 oz. Now the Sigma SV is 24 oz. and has Windstopper, which is very breathable. I think it has the most durable fabric and has the great, large Drop Hood. So really its all your preference. But i would say go with the Sigma over the Gamma. As for the two letter endings, they go as follows: SV= severe (weather), AR= All Around, LT= Light, SL= Superlight, MX= Mixed, SK= Skiing, Comp= mixture of hard (gore-tex) and soft shell and i think thats most of them.
View Details: Arc'teryx Sigma SV Jacket - Men's >