I don't have a multi-device solution. If I did, i would probably give mpd another chance, but i also bet there are some solutions for something similar using mpv, maybe..

I used mpd/mpc/npmpcpp/cmus prior to mpv, but there where several things that annoyed me. npmpcpp/cmus not my cup of tea (i really dislike ncurses programs), npmpcpp has a minimum-width limit and "crashes" if the window is to narrow, which happens from time to time, since i use a tiling wm. I also like that mpv, can display the "album art" if it is included in the id3 tags (which i have a script that does automatically when i "get stuff"). Another annoying thing was that you need to add all new files to the "mpd database", which I guess can be automated, and not really a big deal, but i remember it annoyed me back then. But most importantly, i could never find a way to change the playback speed, i often listen and watch at higher playback speed, and I don't think it is possible with mpd, might be wrong though.

And mpv is as i said extremely rice friendly, so I have a lua script that updates my statusbar as well (TITLE TIME-LEFT).

I also select music/pods/videos with a dirthack rofi/dmenu system. (ls -t ~/porn | dmenu | mpvopen)

The biggest benefit imo to using one mediaplayer, is the global keybindings. toggle play (Mod4+/) is the same for both video and audio, since they are global i can do them without activating the player (i use this for both audio and video, very useful when watching tutorials or lectures and i want to take notes etc). But this can also be achieved with mpd+mpv, by querying mpc and see if it's playing or not and stuff, much cleaner and easier with one player though.