Update. I returned the Phantom and bought two jackets. I went the direction of the Gore Xenon. Wow. Beautiful jacket. Warm. The venting is wonderful. Very comfortable in the teens and lower I'd suspect. I have always layered, but wanted to see how I liked a softshell. I tried a Gore Power 2.0. REALLY impressive jacket. I returned it, though, cuz it had no vents. I am certain I'd have overheated in that thing. Beautfully made, though. Wonderful fleece lining. I sent it back and got the Xenon. Glad I did.

However, I also ordered a Showers Pass Elite Pro. I LOVE that thing. Great venting, extremely light weight. It has some kind of reflective silver-ish inner lining. I throw that over a simple thermal layer (Izumi THermal Elite) with a craft baselayer underneath. That's it. I am VERY comfortable down to 17 deg F. I couldn't believe it. It seals nicely around the wrists and neck. I'm biking in a pocket of warm air. In the 20s I find myself opening the vents to cool off and it's quite comfy.

I like both jackets. If I had to choose one, I'd take the Showers Pass maybe, just for its versatility.

Nice thing about the Xenon, though, is that I'm comfortably warm from the get-go. Body temp never changes. With the Elite Pro I start out a bit chilly for the first 10-15 min until my body generates enough heat to keep me comfortable. After that I'm fine.

Tesgin