Tried 7.1 but did not experience a significant improvement, but IMHO it is all about the room.

Went to 5 x 5Ks + 3 Subs for my desired effect. This worked for me but time and technology moves on at an ever increasing pace.

Always look for bang for buck for the best sound you can afford without compromising your future aspirations.

Best of luck in your Meridian journey

Hector

AV: Thorens TD160B, SME, ShureV15MK2, 500, 598, 861v4, DSP7200.1, DSP3300HC Samsung UE55, SkyHD.
DINING: MS600, AC200, DSP5200SEUG.
STUDY 504, Roon Nucleus + RevB, 808v6, 5200SE, Mac & PC (Touch Screen), Prime+PS Grado GS1000i
HORIZONTAL: M80, MS200, Red Rose Spirit + Sonus Faber Toys, iPad Mini
A capella to Zydeco