I care about immersive writing and believable characters and I dislike it when you can hear the author. It's not possible for every character to think the same way and share the same values - that's the author's opinions talking! That includes main characters across different books/series by the same author. A new name does not a new character make.

I'm also not a fan of books that don't use quotation marks for dialogue. I know it's a style choice but I like them. I don't like getting halfway down a page and realising that several people have been in a conversation I didn't 'hear' and I don't know who said what. At least indicate speech a different way!