Now I've got Sonus Faber Auditor M + Cremona Center M (with Emotiva monoblocks) + Rythmik F15HP + Integra 80.3 (with serious DACs upgrade)
With speakers of that quality and a processor of that capability, I would probably not change to Meridian for home theatre.
SQ-wise I suspect the processor and amplification is perhaps not quite up to Meridian's best but the extra HT facilities you have over a Meridian processor probably balance out that shortfall. I guess you could go for the latest Marantz processor if you wanted/needed Dolby Atmos, etc.
And the room layout you posted would I suspect be overwhelmed by the DSP5500-based system (I imagined your room was ~6m x ~7m) as would your neighbours
