When comparing MPC-HC vs Mellow Player, the Slant community recommends MPC-HC for most people. In the question“What are the best audio players for Windows?” MPC-HC is ranked 17th while Mellow Player is ranked 27th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Supports H.265, and has for over 5 years
Pro Is actively developed by clsid2 on github
Pro Supports frame stepping with Ctrl+Left/Right
Useful for game development frame debugging. Your average user won't need this. VLC has frame advance, but it's hidden and non-intuitive; not clear if VLC can step backwards.
Pro Native
It is written in Qt so it requires less resources than a web browser or an electron application.
Pro AppImage
It is available as AppImage so you can easily try it.
Cons
Con Discontinued
It's been discontinued since 2017.
Con Windows only
MPC-HC supports only Windows operating systems.
Con QML
It written in Qt-QML which ignores all Human Interface Guidelines and make the app look like a web page.
Con Not native
It's using qt5-webengine which is not much different from electron / a webbrowser.