No stuttering here. Maybe connection issue?
I downloaded the file, defo' no stuttering.
I don't think the K-5 had the best video IQ, but it was the last to have decent SR.
It also had the clicking audio issue.
But we've been over this too many times.
If these clips are truly the K-1, then they have better IQ than all previous Pentax DSLR results.
I'd like to see some original files to download and check though
All the above is my opinion of course.
Just reading through the ephotozine review article and they state that the video was shot with MovieSR and that they considered it good.
Quote: Video - There is a built-in stereo microphone, although if you want to record higher quality sound, you can use the mic and headphone sockets on the side of the camera. There are options for setting the recording sound level, wind noise reduction and headphone volume. ISO100 to ISO12800 is available, and you can choose between recording using the full-frame or using an APS-C crop for FullHD video recording. In the video mode you have access to the custom image settings, and there is a "Flat" option available which will be of interest to those that want to adjust video later. Video quality was good, and the built in image stabilisation did a good job keeping video steady, even when recording handheld.
► https://www.ephotozine.com/article/pentax-k-1-expert-review-28884/performance
I've carefully studied their sample and I agree, if that's with MSR enabled then it's much better than previous incarnations.
Having a Flat image setting option for video is a move in the right direction too.