I have a set of Ohm 1000s in a 13 X 25' room with a vaulted ceiling and the sound is extraordinary -- the best I've ever had in any of my homes. (I should have a larger model but brought these from another house with a smaller room and didn't feel like trading up so added a small sub.)
My reference point is acoustic music, though I also enjoy music with amplified instruments. The Ohms have a natural sound and realistic soundstage -- nothing oversized. They do a much nicer job of sounding like live music than anything else I've had. Yes, placement is important, but I've found that is also important with the box speakers I've owned previously.
I'd like to hear a set of GPs but, at their price point, I have no interest in buying a pair when I'm getting so much enjoyment from the setup I currently have.
Of course, as they say with EPA mileage estimates for cars, YMMV. ;-)