Sound
I downloaded version 4 of Musescore only to discover that the format has changed and that the sound reproduction of version 3 files is jerky and stilted. This is not an improvement as far as I am concerned.
Also all my files are now in version 4 whether I use version 4 or version 3. If Musescore cannot be more compatible version to version then it is a big fail and I will no longer be singing Musescore praises to future prospective users.
When something works well DON'T fiddle with it! Just change what is necessary and leave the good stuff alone.
Comments
Right click on a score in your MS3 score folder. Select open with MS3. It should open in MS3. Should you have to do that? Well, that's the way it is right now.
Regarding MS4 playback. MS4 demands a bit more powerful computer than MS3. Check out the information here: https://musescore.org/en/node/339915