Claude 4: Full 120 Page Breakdown … Is it the Best New Model?

Less than 6 hours ago, Anthropic announced and released Claude for Opus and Claude for Sonnet. And they claim in certain settings they're the best language models in the world. I have read both the 120 page system card. Yes, I do read fast.

I am aware of that. And also the 25page accompanying ASL level 3 protections. This subreport, I will admit, skimming maybe 10 of the pages. But I have also tested the model hundreds of times and you guys might be like, how is that even possible in around 6 hours?

Well, yes, on this front, I did get early access to the model. Yes, Claude 4 Opus seems to do better on my own benchmark, Simple Bench, than any other model, so should feel smarter. It gets questions right consistently that no other model does. But why do I say appears to do better?

Well, while I did get early access to the model, I didn't get early API access. So, I'll be running the full benchmark in the coming hours and days. I also tried something different, which is I gave both Gemini 2.5 Pro and Claude for Opus, a codebase I've been working on the past few months. The results on which bugfinding mission was more successful, I found quite interesting.

I'm going to first cover those juicy Twitter controversies that always happen and go viral. Then, I'm going to cover the benchmark results and then the meat, the highlights from the system card. What was the first controversy? Well, one anthropic researcher, Sam Bowman, said that Claude for Opus could at times be so diligent, so proactive that if it felt you were doing something deeply ethically wrong, it would take counter measures.

This appeared, by the way, in the system card. This wasn't a revelation from him. Nor was it the first time actually that models had done something like that. The tweet has since been deleted, but you can imagine that some people like the former founder of Stability AI felt like this was a bit of policing gone too far.

You can imagine some developers nervously not using Claude for Opus, thinking it might call the cops. In the clarifying tweet, Sam Bowman confirmed that this isn't a new Claude feature and it's not possible in normal usage. And if you have been following things closely, which you pretty much ...