This thing is unmitigated trash. It's riddled with design defects and bugs that render it unfit for purpose, some of which are acknowledged by NAD but with no solution. For example: You can't watch 1080p content through it because it reports incorrect EDID info to the source player, saying that the max resolution of the display device is 720p.
Another: Dirac audio processing is well-regarded by many to fix room acoustics, so that was a major factor in the purchase. Welp, the NADs will simply "lose" or stop using your laboriously-sampled Dirac EQ curve at random. Another defect admitted by NAD, but "we don't know why it happens."
An authorized repair guy said NAD simply contracts out their designs, and the gear is often built by a hodgepodge of suppliers out of low-grade components. This was after driving two sets of speakers from one set of terminals apparently caused on over-current condition... which didn't throw a circuit breaker or blow a fuse, but rather destroyed the entire amplifier and rendered the receiver permanently inoperable unless the main board was replaced. Brilliant design.
I have replaced it with a Pioneer, which only suffers from one insufferably stupid design flaw that I've discovered so far (also shared by the NAD): You can't play digital sources through secondary zones ("zone 2" speakers). I mean... WTF.