I just received my T778 a few weeks ago. I am running the front speakers over the pre outs in a 7.2 setup. I had the poping sound at startup, when switching TV channels and when streaming films at the beginning and ending. It also could be heard while navigating in Apple TV. This week my device showed an availlable BluOS update. After running, the plops were gone during operation. I only hear it when I switch the 778 on.
I owned a Marantz Cinema 70s before.
My thoughts about the NAD after a few weeks:
Pros:
Good sound. For my ears, the sound of the NAD is much more focused and emotional compared to Marantz
Good remote control
Good touch screen, very reactive
Good build quality
No HDMI problems with 4k
BluOS
Roon
DIRAC
Compact device for an AV receiver
Cons:
Low noise can be heard in speakers when no content is running
No onscreen menues when you change volume or inputs
Fan (no big issue now, but will it be louder when device gets older?)
BluOS is an external device
Sub outs are not independent
Few HDMI inputs
HDMI 2.0
Price
I found this measurement review (thanks for that) after ordering the NAD, and was a liitle afraid what to expect. When it arrived and I had those plops I was really dissapointed. But after it was fixed, I am happy, and looking forward to see new features in the future.