The main "issue" I have with Claude is that it is not good at noticing when code can be simplified with an abstraction. It will keep piling on lines until the file is 3000 lines long. You have to intervene and suggest abstractions and refactorings. I'm not saying that this is a bad thing. I don't want Claude refactoring my code (GPT-5 does this and it's very annoying). Claude is a junior developer that thinks it's a junior. GPT-5 is a junior developer that thinks it's a senior.
The main "issue" I have with Claude is that it is not good at noticing when code can be simplified with an abstraction. It will keep piling on lines until the file is 3000 lines long. You have to intervene and suggest abstractions and refactorings. I'm not saying that this is a bad thing. I don't want Claude refactoring my code (GPT-5 does this and it's very annoying). Claude is a junior developer that thinks it's a junior. GPT-5 is a junior developer that thinks it's a senior.
[0]: https://www.folklore.org/Negative_2000_Lines_Of_Code.html