I can't list any technical changes off the top of my head apart from needing a blue tick to get your posts seen.
To be clear it used to have a left-leaning bias, around the time when Musk bought it that was shattered and it actually became super balanced. The problem now is that no matter what you do, the algorithm will show you what Musk wants it to show you. It even had a bug a few days ago where every second post was a Musk one, not sure if I was the only one who got that. There's also been instances where Musk has lost it and deleted peoples posts, removed their blue ticks that they paid for, etc.
It's kind of ruined the fun of it.