The music sounds really great, in particular those lovely synth/chord sounds as pointed out by chad! First I thought they were samples inside the AR, but of course, there’s also the AK.
I was listening to the video in the background. The nice thing about it, at least from my perspective: it didn’t sound that different to “OT+A4 jam” videos. I’m sure that the AR will create lots and lots of revenues, but it seems that the same can be done (sound-wise) than with other elektron machines. However, that’s just the case because any sound can be used in the OT! 
In the end it’s a matter of which interface/myth you like the most. At the moment I’m very fine with my 49 keys “interface” for 100 euros 