While I'm enjoying the music so far this season a lot, especially the the team theme or whatever it is they've used a few times, I'm still VERY sad to see Murray Gold go, because he's possibly my favourite composer from his work on Doctor Who, and he wrote countless memorable themes. The Doctor Who soundtracks are amazing, especially from S5 onwards.
I don't even know if the 13th Doctor has a theme. Is it the recurring music they use for the team? It's not used in the same context, so I don't think so.
The previous TARDIS interior was my absolute favourite, so I'm sad to see that go too, but obviously that was inevitable, and I like each Doctor to get their own TARDIS. My only issue with the TARDIS interior is that the big pillars kind of block the wide shots too much. At least with the 9th/10th interior, the pillars were at the edges, not around the console. I love the new exterior though. Very classic influence there, as with a lot of other elements this season.
Jodie is settling into the role more now, and she's already a very good Doctor imo. Can't wait to see how her Doctor develops over the rest of her run.