Recent releases have said something to the effect (paraphrasing here):

"Use <less expensive or older model> for everyday tasks and <other non-critical stuff>. Use <more expensive or recent model> for complex coding tasks, refactoring large code bases, etc.".

Then, the next model/release emerges and the previous "best for complex" gets demoted to "everyday".

Obviously, it's all relative. But, it does beg the question: was the previous model really good for complex coding tasks or no? I mean, how is it now suddenly only good for the "easy" stuff?