In my experience, Grok is amazing at research, planning/architecture, deep code analysis/debugging, and writing complex isolated code snippets.
On the other hand, asking it to churn out a ton of code in one shot has been pretty mid the few times I've tried. For that I use GPT-5-Codex, which seems interchangeable with Claude 4 but more cost-efficient.
Codex is good when you have a clear spec and an isolated feature.
Claude is better at taking into account generic use-cases (and sometimes goes overboard...)
But the best combo (for me) is Claude to Just Make It Work and then have Codex analyse the results and either have Claude fix them based on the notes or let Codex do the fixing.
Ah okay, that makes sense. I do a lot of planning with Gemini and Grok before the coding model ever gets involved, so that might be why I've never noticed a clear difference in output quality between GPT-5, GPT-5-Codex, and Claude 4.
TBH I really should do a lot more pre-planning for tasks - especially on new projects. But it's just so much more rewarding to shove Claude at a quick idea, watch some shows and come back to see what it figured out =)
On the other hand, asking it to churn out a ton of code in one shot has been pretty mid the few times I've tried. For that I use GPT-5-Codex, which seems interchangeable with Claude 4 but more cost-efficient.