And what it is is a summer bag. I've had it for a couple of seasons. It kept me warm on a night (in a tent) when water bottles froze almost solid outside. My only beef with it is this: I have a long, and it doesn't fit into the stuff sack that came with it. This would be an ideal bag for warm weather bike touring. It compresses to almost nothing. I have down jackets that take up more pack space.
Just got back from guiding a 5 day canoe trip in the Adirondacks and using the Phantom 45. It's a great bag for summer temps when a 20 degree bag is just too hot. We had heavy rain during one 24 hour stretch and temps dropped quite a bit at night. The bag performed perfectly and was perfect for the job at hand. Super light weight and stuffs down tiny. I'm thinking about trying it inside a 20 degree down bag in the late fall to extend the temp range. An excellent bag overall and I'd definitely buy this bag again. Snug but not uncomfortable fit.