Initially when shooting videos on the Canon EOS R6 Mark II, I have been using the default HD resolution at 24FPS. But how much more detail do you get with a 4K video? Does 60FPS add noticeable improvements?
Sure, 4K gives four times as many pixels, but can you use that without a 4K monitor? Certainly if you end up cropping the video, the difference is quite noticeable. Here is an example of the extra level of detail you get when shooting in 4K vs HD and 60FPS vs 24FPS.
Each of the videos were cropped to show the details and eliminate large sections of rolling ocean to focus on the details of the buoy.
Note the extra detail in the 4K video.
The playback is much smoother at 60FPS.
If you are publishing for the web at the original size, HD may be fine for most videos. But, if you end up cropping the video, you will have four times as many pixels to work with in 4K. I now have 4K 24FPS set as my default and will use 60FPS for special videos.