1. It plays any local video I throw at it. Other people tell me "It doesn't play some of my videos" but I haven't seen this actually occur. Or when I do, it's because they're using a newer version of VLC which has removed support or changed processing. VLC has terrible license problems and awful feature creep. I had some .mkv files which didn't play correctly, so I downgraded from 1.1.10 to 1.1.5, and they play just fine. That's right, the 3-year old player plays the newest .mkv files much better than the 2-year old player or the newest player.
And unlike mplayer, mplayer2, wmp, and most other players out there, you don't have to goto some random website and download some random codec pack, and install it with who knows what malware.</FUD> All the codecs are included with the program.
Reading this github doesn't tell me why I should use mpv instead of vlc 1.1.5. Actually, it tells me I'll have to go find these random codec packs again, opening myself to possible CSRF attacks and other malware from poorly-secured or malicious codec providers. I'm already trusting the media player install package to not be evil, and I'd rather only have to trust 1 install package instead of it and several codec install packages.
2. I actually downgraded from VLC 2.0 to 1.1.10 because of VLC's terrible responsiveness. I don't know what changed, but it has made VLC 2.0 too annoying to use. The delay is a second or 2, which is a second or 2 longer than it used to be, and a second or 2 longer than it needs to be. When I go from a quiet video to a loud video, and I roll the mousewheel to lower the volume, that volume change needs to happen immediately, not after a 1-2 second delay.
I like that responsiveness is one of the bullet points.
I would have downloaded it and tried it out, but I don't know how to make this on Windows.