"I've used the shell pants for 3 years now, mainly in winter snowy conditions. The shell pants are made of Columbia's Omni-dry fabric, which is touted to be waterproof and breathable. The pants have a full legnth zipper down each side, making them breathable, however, in rain, they are not waterproof. I never had a problem with the pants until I used them in rainy conditions, in which they became soaked after about 3 hours.
Overall, if you are going somewhere where it won't rain, or are close to a quick exit, these are a decent cheaper alternative to Goretex. If you are doing serious back-country exploits, spend the extra $100 on Goretex XCR, and spare yourself potential hypothermia."