Hi, I had a QAV system for a couple of years with a Denon 1909 amp. Overall the sound was good, punchy and fast. The sub can be hidden away or fixed on a wall, but it can resonate up the wall if you do. It doesn't spoil the performance, but if your other half's in bed, she'll not be happy. I know! Surround speakers are great at producing a big sound field, were ever you chose to place them. The only down side is that the LCR speaker is bigger than you might think. My wife called it the tash. She hated it. Its was mounted on the QAV table stand. It'll probably look better if you mount it on the wall. It comes with the wall mount. Overall great with TV and movies. Good with music, but lacks stereo imaging. Superfi are or were doing a great deal on it as well! £299 I think.
Hope this helps you make your mind up.