Alex on Autos did a video on it, explained most of the questions asked here.
The engine is atkinson-ized, which helps explain the lower power. It accelerates about a second quicker than the regular for about a 9 second 0-60. The battery raises the cargo floor 4 or 5" (like many PHEVs), you can see it at 7:30 in the video. He doesn't show the rear seats folded, but they won't fold flush unless they're different from the regular Crosstrek's seats. Heat is resistive and will work down to 14F before kicking on the ICE for heat. About 5.5kwh of the battery is usable.
I think it looks like a pretty neat little hybrid. I'm not aware of any other AWD hybrids/PHEVs/EVs that use a mechanical AWD system like the Crosstrek, so it'll probably get you further offroad.