I have a 5.1 system and the new Atmos mixes on UHD disks are excellent on even on limited surround layouts.
For example, the opening of Star Trek Into Darkness 4K/UHD scene when the spears fly over was much improved over the original BD.
The scene where the shuttle spins around the room benefited from capable surrounds.
I chose quality over quantity (also for SAF and logistical issues).
Oppo UPD-205 x 2 | UPD-203 | Sonica DAC | Emotiva XMC-1 (v3) | Revel Salon2s, Voice2, Studio2s | Benchmark AHB2 x 4 | ATI AT522NC | Velodyne HGS-15 | LG 77C9 | Lumagen 2020 | HDFury Vertex x 2