Thanks very much for the review, Amir!
I own the AVR 390 for two years and use it almost daily in a dedicated, acoustically optimised listening room with excellent speakers, both for music and movies.
Actually I have never actually realised any of these flaws - to me, the sound is just great. Even at very loud volumes, I do not hear any noise or distortion.
However, I clearly hear the massive improvement with Dirac Live being turned on. Other than the poor SINAD, whose audibility can be argued about, this makes a huge difference, even though I already have an acoustically excellent room! I'd never give up Dirac Live for getting a better SINAD.
And there are not many alternatives on the market. When it comes to SINAD, NAD is apparently even less an option than Arcam. And the new Arcam series seems to be having the same flaws, as your AV40 review shows.
Thus, although it is sad that the digital section has these flaws, the AVR390 still seems to be a pretty good option to me for anyone who wants just the best sound in his home.
I am looking forward to your Dirac measurement and am curious what you will be measuring there. Particularly I'd be interested in in-room measurements for localisation accuracy, because this is really the greatest improvement that Dirac Live achieves.