I demo'd the KEF Q300 bookshelf recently along with the KEF XQ20 and B&W 685. The XQ20 is cost prohibitive as it runs around $1500 so I concentrated on the other two. I first listened to the 685 which has gotten uniformly great press from just about everyone. I found it it to be, as I've found other B&W's speakers to sound, a bit flabby or overly bass heavy. I've never been a B&W fan so having brought that bias in, I moved over to the Q300's quickly.
For $599 bucks this speaker floored me with it's poised but potent sound, it's wide soundstage, very nice imaging and controlled bass. It just did everything right. I couldn't have been more pleased with the presentation. It also remained unflappable and not compressed sounding at high spl's. Like I said, a poised speaker and at a great price too. They look rather boxy, because they are, but that uni Q driver is something to look at with the grills off. I demo'd them with the grills on. At 10% off, they're a bargain. I'd recommend the Q300 in a minute.