I was initially hesitant dropping this much money on a jacket, but you do get what you pay for with technical gear.
I didn't really have a use for this until ice climbing season. Lows high in Ouray were -3/7 but once you got in the sun the ice started dripping, and as the temps came up later in the week it was like climbing in an icy rain. Started climb with puffy but nearly died of heatstroke even at -2. The ability to ventilate this jacket while you're working hard and keeping dry made climbing much more enjoyable. As I wasn't soaked while on belay I didn't freeze my ass off either.
So the jacket does exactly what it was designed for. Breathability, waterproofness, articulation, and it doesn't sneak out from under your harness. Excellent piece of gear. I bought the Lg thinking about layering and while it's fine a Med would have worked too.