Still trying it out...
...but it appears to be waterproof. It does NOT appear to be breathable, so I'm not sure how well it will work for riding. Does keep me dry on my way to the barn and back when it's raining. :)
Rated 0 on a scale of minus 2 to 2, where minus 2 is Runs Small, 0 is True to Size and 2 is Runs Big