Personally, I love it. I went from a 65 TCL to this. The sound is better, the picture is better, the brightness is better so cannot complain for one bit. As for the motion issue, I’m not an expert, all I can say is that it does not trouble me much but can notice it. I’ve just updated to the K0901 minutes ago so too early to say as the pictures settings went back to default... I just finished watching Gardian of the Galaxy 2 in 4K Dolby vision and it looked VERY GOOD!
As for the OS, I solely use the 4K Apple TV as I watch streamed TV with MyCANAL and Molotov TV (the frenchies out there will now what this is). Plus Netflix, Amazon and Disney....
In my opinion, for the price, it cannot be beaten at the moment!