AV processor choice - Mac MX123 vs NAD M17 v2i

auxinput - Actually the MX123 does come with firmware updates.
From the MX123 manual page 26

Setup Menu>General>Firmware

The MX123 A/V Processor can be setup to
automatically download and install new firmware to make sure the unit has the latest updates. Updates can also be shutoff or manually performed. 

I wouldn't really say that Dirac room correction makes a better "stereo" sound.  The quality stereo sound is more due to the analog output stages and power supplies in the processors.  It's difficult to say which of these may be better.  Both have pretty good power supply sections.  Both "appear" to have switching power supply for digital (which it actually very typical). 

The NAD is built on a modular and expandable platform where you can plug-and-play different modules for different things as new technologies emerge (such as HDMI 2.0 and HDR as well as Dolby Atmos).  NAD does have firmware upgrades, but not very frequent (the latest firmware upgrade is dated "03/04/2020").   There is a Dolby Atmos module for NAD that adds 4 height channels, but they are all RCA output.

The McIntosh MX123 has XLR outputs for 13 channels (including Dolby Atmos height channels).  This might be better depending on what cables and amps you are choosing.  McIntosh will not have firmware upgrades at all. 

Maybe i will get mac too.  Have two rooms.

I really like Dirac, but McIntosh and NAD are going to sound different so it will really have to be up to what you prefer.

Hardly an impartial view. Spell my name correctly.  Its Jumia.

Juna the m17 sounds really good


It is slso upgradable as the audio and video tech m ology is on swappable cards

Also the m17 has fantastic streaming built in

Give us a call we sell nad Audio control and anthem

Dave and troy
Audio intellect nj