Composer writes the worst, stupidest, most naive and straight up brains-dead code you could imagine. Fast and cheap is about all it’s got going for it. I mostly use it for “sort these lines alphabetically” and stuff that’s a smidge too complex for regex find/replace.
I primarily use composer. I wanted to build something from scratch recently and, thinking I was missing out on something, I got Opus to build it. I wasn't blown away. I gave the same prompts to composer and the code it came up with different but similar in quality. I ended up progressing with the composer code because it was easier to progress with improvements due to its faster response time.
It’s starting to feel like people need to say what language/stack and problem space they’re working in. It would be interesting to see why we’re seeing such wild variance.