Bringing back this thread because I've got information, man! New shit has come to light!
I was hoping to get some rides in and get some pictures before posting a full report, but my hand has been forced by certain developments. Foehn is having a sale and Brise pants are currently CA$99.97. I thought I should get certain facts out there so those that are interested can score a deal while it's still available.
First off, I was worried that the Brise would be too aggressively tapered and wouldn't play well with knee pads. I was wrong. They fit over my large Chromag Rifts with zero stretching in a standing position and even fit over fairly bulky size-L first-gen RF Flank Knees (the slip-on ones) with mild stretching. Actually significantly less stretching than whatever super-bulky monster pads than the model is wearing with the Tobin bike-focused pants in this picture.
Even though the cuffs have zippered openings, I can't hike them up enough to be able to slide on the knee pads while wearing the pants. It's definitely a case of put on the pads then pull the pants up over them.
They are exactly a 32" inseam, as advertised.
It's not obvious even from Foehn's close-up pics of the pants, but they use 2" elastic for both the cuffs and waist. The cuffs fit snugly over the uppers of my Shimano XM9 boots, but I think they will probably work their way loose over time while pedalling. I'm tempted to rivet in a lace hook to make sure they stay in place, especially since the elastic should be better suited to that kind of abuse than poking holes in the Shoeller.
With a lace hook, I think that the 32" inseam will actually be enough for me. If they were at least a 33" inseam, there would probably be enough material that they wouldn't stretch as much while pedalling and tend to work themselves off the boot. Keep in mind that I normally would wear a 34" jean with shoes.
Before I scored the cheap lightly-used Brises (cheap enough that I was willing to gamble they wouldn't work with knee pads) I got a deal on some IXS Carve AWs. The IXS's are only a 28" inseam, so they're kind of goofy water-proof man-pris on me, but I'm working on a cunning plan to avoid saucilly flashing my ankles at he elements. The IXS's do have a few interesting features that I need to document for postarity wih pictures in case there are any clothing designers reading this that actually create pants for average mountain bikers.
So watch this space for updates with pictures and reports of the actual real-world waterproofness of both types of pants.