TFoxwrote a review of Race Face Aquanot WPB Bike Pant - Men's on November 4, 2010
I will give these pants 3 stars. The rating means "Adequate for the job," which very much depends on the job here. On a handful of occasions I have ridden these in steady rain on my commute, which is about 30 minutes door-to-door. The fabric from the start never really repelled water (like some weatherproof fabrics with a DWR treatment), so it gets soaked quickly. By the end of the ride, the pants are definitely damp on the inside from the rain (not sweat), evidence that the 5000K breathable/waterproof membrane is not quite up to the task of wet weather commuting. In fact, it's not much drier than my softshell Patagonia guide pants with their DWR. I recommend wearing thermal (cycling) tights or other long underwear underneath, which keeps the cold and dampness off the skin. One plus is that they are breathable/comfortable enough to wear when it isn't raining.
Overall, they are a fine deal when purchased on steep discount (I think I got them for $45), but if I had the choice to buy something again, I might actually spring for a higher price point to get the quality I want. I'm finding that quality rain gear is not something you can really scrimp on.
Another note: they have a fairly tight fit, as the other commenter noted. This is generally a good thing for bike pants, but this fabric does not stretch at all and the cut is a tad restrictive. Not a huge deal when in the saddle on a commute, but I find myself hiking up the butt occasionally and I don't think these would be great for hard or long workouts on either road or XC.
Last thing: the side zips are long and prone to letting in weather. I think they could have been designed a little better.