Thinking about trying iCloud Music Library? Don't. It's a bag of hurt.
iCloud Music Library's problems start showing up after installing iTunes 12.2 on your Mac or Windows PC. Apple's forums are full of comments from users saying their album art, song names, and album titles get jumbled. The Who's Quadrophenia album art, for example, could be replaced with Billy Holliday's Lady Sings the Blues. Try to play Cream's Sunshine of Your Love, and you might hear Vertigo from U2 instead.
Some forum posters are saying other metadata for their songs and albums has been scrambled, too, and multiple copies of songs are appearing in their libraries.
One Apple forum poster said,
Got home and installed 10.10.4 and iTunes 12.2 on my iMac. It asked to turn on iCloud Music Library and I accepted. All of the sudden it starts overwriting my album art with completely wrong art (example: Weezer showed art for a Radiohead album) on both my iMac AND my iPhone, screwing up metadata by putting random songs in albums where they didn't belong (there was a Cursive album where the first track was listed as a Foo Fighters song). Even worse, when I'd click to listen to certain songs, it would play the wrong song/artist, like the metadata was hijacked.
The only fix so far is to restore your iTunes library from a backup and don't reenable iCloud Music Library.
As if that isn't enough of a headache, music uploaded to iCloud Music Library gets wrapped with Apple's Fairplay DRM copy protection. That means all of your music stored in iCloud Music Library copy protected regardless of the source. Translation: CDs you own and rip to your iTunes library will get copy protection added so if you stop using Apple Music you'll be locked out of your own songs.
In contrast, iTunes Match simply stored your copy of songs (assuming they aren't available through the iTunes Store) or gave you DRM-free versions from the iTunes Store. You didn't need to worry about maintaining subscriptions just to play the music you already own.
Kirk McElhearn offers up a great description saying,
With iTunes Match, when you download a matched or uploaded file, you get either the iTunes Store matched copy, or the copy that iTunes uploaded of your original file. When you match and download files from iCloud Music Library (without having an iTunes Match subscription), however, you get files with DRM; the same kind of files you get when you download files from Apple Music for offline listening.
In retrospect, the DRM layer Apple is adding to the music we own shouldn't have been a big surprise. TMO's Dave Hamilton found a big hint in Apple's updated iTunes terms and conditions that said, “You shall not be entitled to burn Apple Music Products.”
iCloud Music Library is a part of Apple Music, so as such Apple is simply enforcing its new terms. Unfortunately, those terms are a little overreaching since they're also applied to music we own outside of the iTunes Store ecosystem.
Apple Music's streaming music stations and Beats 1 Internet radio may be running just fine, but it's clear iCloud Music Library still needs some serious work. If you're already using iTunes Match, don't transition to iCloud Music Library for now—and if you aren't using either, leave well enough alone and stay out of Apple's online music storage.
Update: And now I have a follow up to my disaster assessment.