I decided to finally jump on board yesterday and activate my 3 month trial as a similar 3 month offer with Spotify was ending today.

I'm finding that it's "helpfully" replaced a LOT of my album art which I'm rather annoyed by. Anyone else had this happen ?

I'm just hoping it doesn't screw it up completely when I end the trial - it took me around 2 years to update and tag my entire collection so I certainly don't want to have to start that all over again.

#edit

Googling around briefly reveals this is an actual problem for a lot of people which is hugely annoying. Some have even said that re-syncing after a workaround blanks out a lot of artwork as well.

Ugh .. looks like the library is screwed no matter what i do. The main fix is apparently to turn off iCloud music and then revert to a previous library itl file which restores all of the original album art in the correct places.

Since I reformatted my PC a few weeks ago, I don't actually have any previous library folders ..

Ok, i'm sure you'll be pleased to know i've fixed it. Luckily, i realised that my local library was actually untouched as i'd activated my free trial on my phone, so it was just a matter of plugging in and re-syncing after turning off all of the various iCloud options.

Everything is now back as it should be.

I did the three month trial when it started last year and continued for another three months. I too found it had flaws. Replacing album art with odd alternatives as the OP says. Plus I found it would replace songs I had from other sources such as cd's were replaced with alternative versions. Not the version of the sing I owned. I have my collection on my iPhone and use it a lot in the car. It would randomly stop playing or a track I added offline would come off the offline list. It was great to be able to add all these tracks but I started to lose track of my own collection. Cancelled in January and to be honest it was good to have my own collection back with correct versions of songs. The album art alternatives don't go away though. Apple Music is a great service for content and the for you section. But it does seem to mess around with your own personal collection.

I got an Apple Music sub, got it on Family Sharing which although is more expensive it works out better value if you share the cost.
I have had the odd issue where some of my own non iTunes tracks were replaced by something else that had an identical track name. Resolved that by slightly altering the track name and then uploading the album or track to iCloud.

Seems like I might have fixed it just at the right time then before it had a chance to do any lasting damage.

I've backed up the library now as well, just in case.

Good idea. If I remember I'm sure some songs from my collection disappeared completely or were just greyed out in the onset list. The only way to get them back was to switch off Apple Music.

I've used iTunes for years for my personal collection and, like you, have spent a great number of hours tagging files correctly and downloading album art.

I've tried Apple Music a couple of times and each time it totally screws my personal library. After the month is up I always find myself moving back to Spotify.

I'll most likely go back to Spotify as well when this trial is up. It's three months so I might as well take advantage of it. It's hobbled somewhat by having to turn off the iCloud settings but if i hear a song i like, i find just sharing it to my Facebook page is an easy way of reminding me to get it ..