I get lost in the new Get info... it seems a more simplified version.
It's not simplified. It is designed for looks instead of functionality, and the functionality is severely broken.
1. Going through info of several items to see if they are consistent is impossible because the formatting of the info depends on the data.
2. Command-N / Command-P for next and previous don't work if the cursor is inside an item that can be edited.
3. You can't edit the year when Media Kind = Audiobook. WTF????
4. Audiobooks have a field "Release date" which seems to be fixed sometime in June 1905. WTF squared????????????
5. You can't add comments without first adding a "comment" field.
6. You can't change the "media kind" once a song is added to iTunes Match.
7 After adding songs, you get warnings about editing getting lost because iTunes Match is running. This is bad. What's worse is that editing is getting lost while iTunes Match is running. For example, change Media Kind of 80 chapters of an Audiobook for "Music" to "Audiobook", one or two files won't get changed.
8. After changing the media kind to audiobook, you can't change the year, so you change back to music, edit the year, change back to audiobook, one or two files won't get changed (see above).
Any more serious bugs that you know? Seriously, there is "testing" and there is "trying out everything". It looks like many things have not actually been tried, or obvious bugs have just been ignored. And that's just "Get Info" which is lots of significant and annoying problems in just one bit of minor functionality.
Note: 1000 thanks to Partron22: "Get Info" with the option key held down fixes problems 1-5 and 8 is not the annoying problem anymore.