Welcome to ClubSNAP.
Best starting point is to define your requirements. State clearly what is 'must have', what is 'good to have' and what is 'nice to have'. Then head over to the review sites and check the features and functions. In addition, you can also browse through the other forums here focusing on MFT cameras.
Samsung NX1 is excellent in the AF department. BUT H.265 codec was ahead of it's time and Samsung has since closed down it's camera division entirely. So collectors can buy it as a relic of unfulfilled potential.