The first improvement (Media Foundation by FFMPEG) could be significant. Currently, VALVe generates large shaders to re-render those Media Foundation videos into other free codecs. These shaders can be several gigabytes in size for some games with lengthy videos. With FFMPEG, those videos could be played without being re-encoded as shaders.
I prefer a simple style (just the folder icon, without the dolphin); but everyone have their own preferences. So… 🤷
As always, it can be customized for your own taste.