I believe the Core is currently available on Amazon.
Re. filling a large room: it sounds really good, but perhaps not quite enough bass to fill a large room, depending on much bass you like. I am playing it in a large room with very high ceilings, and I am very impressed with the sound.
I know Mass Fidelity raised enough money that they also made a wireless subwoofer to go with the Core. Not sure if it's been released yet.
