I have mixed.
It is immensely unpopular among the Naim set and when you go and buy your Naim gear there will be relentless pitching of Naim equipment along with the associated eye rolling!
That said, I have a Naim AV2, connected to a Arcam DVD player along with a Pass 3X amp. Many people do the Arcam/Naim thing given the British connection and Naims lack of a Dvd player. The Pass amp always draws some sort of comment!.
To answer your questions, I am very happy with the Naim processor unit and feel that it sound better with a Pass amp then a Naim Amp. I am thinking of doing the opposite of what you are doing and getting a non-Naim 2 channel and reference player which can be integrated into the AV2 Processor.
At the end you touched on what is the biggest pain however, the cables and the DIN connectors. I was told by a Naim dealer that Din to XLR is not worth it. My Pass Amp has XLR's and was told that unless your CD player is "truly" balanced there is no point using the XLR and even then its questionable in its benefit. I wonder personally if that has to do with the Din connections?
I would also note that to ask a someone if they like their Naim equipment is a waste of time. There is definitely a Kool-Aid factor here.