1. On the ignore instructions point: using Cursor with Claude as the underlying model is quite different from using Claude directly through Claude Code. The agent/tooling layer can have a pretty big impact on the behavior.
2. On verbosity: IMO, Claude's default writing style tends to be more verbose than GPT's. GPT models are generally more concise when coding, while Claude often explains more. That said, I think this can be mitigated quite a bit by how you harness the model.
3. I agree that it’s worth trying new models. The pace of AI development is so fast that models can change significantly in a short time. But I’d also suggest trying different agent tools rather than sticking with Cursor alone. The tooling and agent loop can make a big difference too.