Hi Jack,
I had the same concerns. I contacted the manufacturer (OmniMount) and they said the 10 pound rating was on the conservative side for liability reasons. It will actually hold a few more pounds. So I figured the 11 pound QS8 was within the margin of safety. They also make a ceiling mount that is rated for 20 pounds, but the shaft thread is 3/8", so it won't fit into the back of the QS8 without extra hardware.
After mounting them I can say these mounts are very sturdy and they don't show any signs of being too strained holding the QS8's. My SVS PB2+ in the same room really shakes things up, but these mounts are still very stable.
I just took a few photos of my eggshell white QS8's with these mounts,
click here to see them.
Jason
