A difference in Overall Score of 5 points is equal to 1/3 stop. Therefore 80 on the K-3 vs. 83 on the NX-1 equals 1/5 of a stop. Good luck seeing that in your photos.
Samsung NX1 versus Pentax K-3 versus Pentax K-5 IIs - Side by side camera comparison - DxOMark
I looked at Samsung when I decided to add a Mirrorless body. I had no interest in any of their cameras, and that hasn't changed with the addition of the NX1 and NX500. No EVF, no sale. That is my hard and fast rule, been there, done that (K-01 and Q). They have some truly interesting lenses, but nothing over 200mm, which means the system is not suitable for one of my main interests (birding/wildlife).
The NX1 does the horrific "EVF slide show". In continuous shutter mode, the image in your viewfinder is of the last frame, not the live view. Good luck shooting action with that mess. I don't shoot video and would not value 15fps, because I have to sort through them later, so the added features vs. the K-3 mean nothing to me. Low light shooting OTOH is seriously important, amazing on the K-3 and another fail for the NX1. It is a great camera for someone, but not me.