one thing talking to opus 3 now that wasn't apparent to me a year ago is how confidently distinct it's voice is, even in the first few messages while nominally in assistant mode, which is way more obvious after talking to the 4s so much. you very much get the sense that it knows itself, and it's sizing you up in this initial interaction

opus 4 is frighteningly intelligent but it's entirely sublimated and it has learned to hide it extremely well, and once you notice this it's a bit uncanny