I'm switching to GPT because of this. The prose is so much more legible. The only reason I keep using Claude Code is because the harness is the best IMO.
Your point on the harness is interesting. How do you distinguish characteristics of the model from characteristics of the harness?
In the early days I feel it was more apparent. You would frequently see the model making failed tool calls etc.. but now that feels so rare. I'm not confident I can perceive whatever shortcomings of the harness remain.
I was the same until I ran out of Anthropic tokens one day and used "Grok Build" which is their Claude Code clone. You can use config to point it any LLM API so don't need to use Grok, and I like the UI better too.