I wore the Sedition 2 for a few runs the other day. I wasn't hiking and it was cold so I can't comment on the breathability but I'm sure it will be an improvement on the HyVent.
Compared to other XCR jackets I think it won't be as breathable because it has a thin fleece laminated to the inside and most XCR hardshells I've seen go with a much thinner "scrim" laminate. It will probably be a LOT warmer though and it does have big ass pit zips to vent.
One word for the snowboarders out there - this is NOT the jacket for you. The torso is too short and therefore the pow skirt rides up/pushes your pants down when your getting your board on.