I've always wanted to try the QS8 surrounds but was leary about not matching my fronts & center. I've heard both sides on the topic...some say all speakers should match & others say as long as the front stage is timbre matched the surrounds can be from a different manuf. I know about the return policy but I'm just sending out feelers because I'd hate having to send them back if they didn't work out. So the bottom line is this...can surrounds co-exist with other speakers without causing issues. Thanks

Yes, I'd expect that you'll enjoy QS8s regardless of your brand of front speakers. A word of warning though, you might consider replacing the KEFs once you've heard the QS8s. Yes, they are that good.

Edit: I should mention that I have a relative who sells AV gear. He wanted me to buy Focal surrounds. Nice speakers, but after listening to both, I kept the QS8s.

I think out of all mixing and matching possibilities having the surrounds different than the fronts would be fine.

My QS8s don't match my front speakers and it doesn't bother me at all.

I agree with the rest of the posse. I've heard QS8's in a setup with Monitor Audio mains and it was just lovely.