Cham,TBS 6903, EBS Pro, and PotPlayer, but I do not have a UHD display, only 1080. Looks great though...
What video card do you have? I have a TBS 6983, EBSPro & Pot Player on a moderately fast i3 with a middle-of-the-road graphics card (monitor is only HD), but the display of NASA stutters. If I record with TSRecorder (or whatever it's called in EBSPro), and then play back with Pot Player, it's a lot smoother on the video, but the audio stutters.
Also, I have VLC set up as the default player in EBSPro, but want to change it to Pot. I can't remember or find out how to do this. Is it simply whatever player is set up as player 1?