I replaced direct-radiating with the 8's and will never look back! Very enveloping for surround, but I don't listen to a lot of multi-channel music so no comment there.

I have mine mounted to 5' tall stands. I used the included TEE bracket that comes with the Q's. I modified the stands which supported my old surrounds. I mounted the bracket to a couple pieces of wood which I then screwed into the supports of the stand. It actually mounts as if a wall were behind them, only there's vertical uprights there instead.
The stands were custom made for me by a friend many years ago, and these are the 3rd pair of surrounds they have supported. Good planning on my design I guess! If you like, I can send you a PDF file showing how I mounted them....just give me an email address!