rev wrote an answer about Arc'teryx Squamish Hooded Jacket - Men's on March 27, 2012
This is a windshirt, not a rain shell. It can get you through a short rain, but it's not going to keep rain out during a downpour, long or short. If I were to bring the Squamish on a backpacking trip, I'd bring a DriDucks poncho or jacket along for anything other than a short short or sustained misting.
It's cheaper not just because it isn't Gore-Tex- it's cheaper because it's a simple nylon wind shell and has no kind of WPB membrane like Gore-Tex or eVent. It's made of a very light 15D nylon- it's going to be reasonably resistant to abrasion, but this is ultralight gear. The dead bird logo doesn't impart magical properties that allow it to overcome its fundamental nature. :)
It's also not extremely wind resistant- nowhere near as wind resistant as any WPB shell. Far less wind resistant than anything made with PowerShield, Windstopper, etc. For those who want something like the Squamish, that's a good thing- less wind resistant means more breathable. A jacket like this is indispensable when on the move, especially when it's cold.
For what it's meant to do, the Squamish is exceptional- but you're asking for trouble if you get one expecting it to perform like a bomber hard shell made of a 70D nylon or polyester.