I noticed that when opus 5.5 was on parts on my codebase that had lots of 5.0-generated comments, it picked up its style. Unfortunately I think 5.5 has been trained to mimic what it sees so that you can ease up on the instructions, but this does mean parts of your codebase that 5 touched will be somewhat viral.

GLM-5.3 does the same, funnily enough.

I gave it some vibecoded patch someone created with Opus 5 with the task of together figuring out the real root cause and what to do about it.

Big mistake. The rest of the session was all claude-speak up until I've rage-quit and restarted with Qwen and no context other than "here's what I think we've missed in the current implementation. How could we approach that?"

GLM felt like it got at least 20 IQ points dumber just from being exposed to claude's writing.