I did the update couple hours ago on my Nd5XS2 into Ndac and I can’t say if I hear a real change, I have been listening for hours yesterday evening and have been listening to the new firmware this morning for a couple hours too.
It sounds lovely, but again so did it yesterday 
I have to say I would usually be on the sceptic side of the hobby as I just returned a 2.5k Nordost QB8 that I had on try and that I didn’t really like or feel like it made a significant change, especially not for that crazy amount of money…, so I would fail to see how an upgrade that wasn’t aimed at improving sound could benefit the SQ in any way, but hey maybe I am wrong and maybe the patchnote doesn’t get into some secret tricks from naim.
I have however ordered a DC1 BNC cable to replace my Nordost blueheaven I got with the streamer and that I always felt sounded a bit edgy compared to a chord clearway I had on spare and tried a couple of times, I’m curious to see what the “Naim sound” full loop can sound like. (I think I have an issue with Nordost as I really believe they are selling air, especially with some of their Qv2 and other “plug in” miracle blue LED dodats for the price of gold)
Long story short, I like this update, haven’t had any issues with it, update took about 5 minutes over wifi, no volume issues etc.. and I am still very pleased with how everything sounds.
I will however surely be influenced by the confirmation bias as everyone seems to love it so much, free upgrade hehehe!