Codex vs. Claude Code: Which is better? My one-week trial says no definitive answer

As a research slave who codes entirely by modifying my senior's old scripts, I tried throwing Codex and Claude Code into the same project to make them battle each other. The trigger was seeing news that Codex hit 20 million weekly active users, with comment sections already screaming 'Claude Code is done.' My advisor was still using Claude Code to tweak experimental code last week, but this week someone told him to switch. He asked me to test it out and give him a conclusion.