The player position Bug Fixed
This bug that prevented setting the player position while the player state is paused is fixed in iTunes 12.4.1
iTunes 12.4.1 Released
Apple has released iTunes 12.4.1 which fixes the Crossfade bug, problems with Voice Over and Up Next, and restores the Reset Plays and Convert ID3 Tags features.
NEW: Reset Plays
Even though I had posted a script workaround to emulate the now-removed "Reset Plays" feature, several users had suggested adding a few additional settings. Plus, some people were just not sure how to get that script onto their machines.
Reset Plays is a downloadable variation of that original script that, in addition to resetting Plays and Played Date, also resets Skips, Skipped Date, Rememebr Playback Position and the played property.
Can't Replace "Convert ID3 Tags"
Apple has removed the "Convert ID3 Tags" command in iTunes 12.4. I don't know why. I didn't use it much myself but many users needed to convert the metadata ID3 Tag version so MP3 files imported or converted with iTunes would be compatible with other players.
There is no AppleScript command or property for iTunes that is related to this so no purely-AppleScript workaround is possible. Interestingly, SoundJam's AppleScript dictionary had a property to read—and possibly write, don't recall now—the default ID3 Tag version. It didn't make the trip to iTunes.
[UPDATE: the Convert ID3 Tags feature has been restored in iTunes 12.4.1.]
UPDATED: Smarts v1.3.2
Smarts will save and store the criteria of an iTunes Smart Playlist—the smarts of a Smart Playlist—as a template so you can reload it into iTunes later.
This latest version makes accommodations for changes in iTunes 12.4.
Smarts is a free download from The Mac App Store.
Did I Forget to Mention This?
The selection property will contain references to tracks selected in Apple Music. You can get properties of these URL tracks, but you can't set them. That would be dumb*.
I neglected to note this earlier because I was falling all over myself about current track and current playlist also being able to reference Apple Music items.
{UPDATE: *I stand corrected. You can set the loved property of the tracks in a selection of Apple Music tracks.]
EQ window No No
The EQ window inherits full screen from window now, but setting full screen of EQ window to true will error.
Of course I tried it. Thought it'd be fun to see a full screen-sized EQ window.
Slightly disappointed.
Tidbit on minimized
The browser window property minimized has been removed ("is the small player visible?"). This was related to the old behavior when minimizing the main window would switch to the miniplayer. Good times. I seem to recall this mechanism had different behaviors in various versions of iTunes. Anyway, not needed since the "small player" can be detected using the new miniplayer window class.
Slight Growing Pains Continue
The podcast value for media kind will confuse older scripts that look for the podcast property of track. The podcast property for track ("is this track a podcast episode?") was removed in iTunes 12.4. Similarly, the iTunes U property of track has also been removed and is now a value for media kind.