Thanks. Ideally, I would add another two 5200s in for surround. Possibly a bit of an over kill, but the main thing stopping me is space. I would need to bring the rear wall of the cinema in another 500mm and aside from the mess (rear wall is custom build into a curve), the room is only 5.2m long. I had thought by replacing the rear 5200s, with four 3200s, I could place them a little higher and provide a more full surround experience.

Don't get me wrong, I love the 5200s for the front (have 3 x vertical), but not sure if I would notice a large difference replacing with 3200s for surround.

I am keen to go 7.1 with the HD621, as I only watch Bluray and when not movies, then games on the PS3. I have a TV for, well.. television smile

3x DSP5200 L, R and C (all vertical), 4x Triad Silver in-wall surrounds and 6x Triad Silver in-ceiling ATMOS speakers, Triad Silver subwoofer, Denon AVR-X8500H, JVC DLA-7500 4K projector and Screen Research 120" AT 2.35:1 screen.
Apple TV 4K and Oppo UDP-203 Blu-ray player.