You may already have read this blip, but just in case not, click here
for MontBell's description. And yes, it is an ePTFE membrane as well. I got that in separate email exchanges with MontBell.
I've been using MontBell's Peak Shell
jacket for almost three years now, and have been very happy with it. Back when I was shopping for my wp/b jacket, I wanted both high breathability and venting options -- and that basically narrowed down to two: eVENT vs. MontBell.
I believe that eVENT is the more breathable of the two, although the difference is probably very slight, given that both laminates are air permeable. Unfortunately, the eVENT jackets at that time had no venting options aside from the front zip itself. The Peak Shell jacket, on the other hand, came fully featured with extra long pit zips, hand pockets, adjustable hood, etc. and weighed just 11 ounces.
I've worn the Peak Shell snowshoeing uphill for two hours in the high 30's -- and all throughout, I was complety dry and comfortable -- and never needed to unzip even the front zip at all, never mind the pit zips. Afterwards, I took off the jacket and checked my baselayer just to be sure -- and yup, it really was totally dry, as was the inside of the jacket itself. Still, I like the fact that the jacket comes with different zips for venting -- for use in warmer or more humid occasions.
Separately, I once read a post from a hiker who owned both ID eVENT and MontBell Peak Shell. He wrote that all zipped up, the ID was more breathable, but with pit zips, the MontBell was the more comfy and versatile of the two.