I also did a comparison between the 7D-II and the NX1 (see attached). The 7D-II (with it's 14% smaller sensor) appears to be an equal to the NX1 in terms of high-ISO noise and apparently offers more accurate color SOOC.
You are free to make up your own mind, but so far I cannot agree with people who say that the NX1's high-ISO noise performance is close to "some" current full frame cameras, I'm just not seeing it. Even the "worst" current full frame sensors (the 6D/5D-III) are better it high ISO. Anyway, this has just been my subjective assessment of moderately high-ISO. I'm keen to see actual measurement data from DxOmark and others.
I did a similar test in another thread and saw that while the NX1 is about equal to the 7D2 for high ISO in bright light, it's worse in the DPReview lowlight test with both downsampled to 8MP and a small amount of chroma noise reduction applied. The quality of the NX1 noise was odd and detracted from the image quality.