I've been using this on and off for a while, since v1.3 in September (and swapping with InnerTune which seems to now be abandoned..) but I have a few glaring issues with it as a daily driver.

Downloads are a mess. Tap download and it may or may not download. The download notification frequently becomes persistent for some reason, even if the downloads have finished and you kill/restart the app. Restarting my phone will get rid of it. Accessing auto cached songs is hit and miss if you don't have internet which completely defeats the point of it. Also there's no download management so whatever you download is now what you have saved unless you delete the library and start over...

The library page is ass. There's no breakdowns by song or artist or album or any other category. You have favorites, followed, most played, and downloaded along with a bunch of playlists under that and finally a recently added list. If I want to shuffle my library I go to downloaded (because I download everything) and just tap a song which will start playing but take the UI ~10 seconds to catch up while, I'm assuming, it builds the playlist.

When I connect to a bluetooth device and my screen turns off I immediately lose the bluetooth connection. Turn the screen back on, reconnect, start playing the music again and it works fine after that. This only happens with SimpMusic. Occasionally have had issues connecting to bluetooth and the app says it's playing via bluetooth but when you change the volume it says it's playing via phone while no audio is coming out anywhere. This is usually paired with a "something unexpected happened" error message and app restart (have had this issue loop before for hours, phone restart fixed it).

The music player notification stops working regularly and just won't come back until I restart the phone.

Intense lag after listening for a while.

No dislike button to help avoid songs.

And maybe my last complaint which is relatively minor to the other things, but under some categories, like new releases, it will show the art, the name of the album/single and then say "Album" instead of the artist which probably annoys me more than it should and may be a result of the other issues adding up.

No, my last complaint is the copying of Spotify's horrible UI, but somehow it's even worse.

On the upside, sponsorblock works well, my YTM playlists are all accessible, even ones I forgot existed from the GPM days, and the app does work for the most part. Long listening sessions work better than Innertune or Vimusic did. Hoping to see this continue to be worked on and improved, it still has a long way to go though.