My unit is back from M. Firmware upgraded. HDMI problems resolved.
All other products being equal, M's customer support would keep me coming back.

Main System: Trinnov Altitude 32-8-16, 271, 2 x 8KXE, 1 x 8KPP, 6 x M6 Surrounds, Rel No.25, Oppo 203, Zappiti Pro 4K HDR, Roon, WiiM Mini.