Just got the NX1 and I was very disappointed you have no manual audio control while filming! I thought that was a pretty basic thing in just about every camera in this range of video centered cameras (7D2, 5D3, GH4, A7s, D750). I am looking everywhere for that control and it doesn't appear to be there. Also, I wish it had a dedicated movie spot on the dial so I can keep separate settings for movie and photos. So far I set up one of the custom modes for movie shooting but obviously those reset back to the saved state when I go back to manual or another custom mode. Not very good for bouncing between video and photos.
Also, you have all of these buttons but few options for customizing compared to many other cameras I have used. I don't use the AEL button much but you can't change it to something unrelated...you can just change the affect it has when you use it which is limited.
So far I have yet to pass judgement on the quality but the controls and customization are more in line with cheaper cameras and less in line with something like the GH4 or Sony A7s. This is definitely not one of those. Also, you still have the 30 minute recording limit unlike the GH4 (can't we get rid of this and just pay the tax!!! How much could it be?).
I don't think I can get over not having audio control while filming. Very limiting to me and mandates an external recorder which I was hoping to make optional. Quality might be good but usability is not quite in the league of the GH4 and A7s...at least for video.