The main improvements for me since Musk took over:
- No more unjustified blocking of accounts by activist moderators, as far as I can tell.
- The new "following" timeline now shows all and only the (re)tweets from people you follow. No "recommended" or "liked" tweets interspersed like before.
The main thing that got worse:
- For accounts with many followers, it shows not the most relevant (liked etc) replies on top, but the replies of random people who bought Twitter Blue. I mean X Premium.
Overall I would say it's significantly better in my opinion.