I've been using fully Claude Opus 4.1 in my terminal setup for coding, reasoning, and agent-like tasks. it's been solid for complex workflows. But now that Sonnet 4.5 is out, I'm wondering if I should switch. From benchmarks, it seems to match or beat Opus in areas like coding (higher scores on SWE-Bench and agentic tasks), visual reasoning, and handling nuanced instructions with better efficiency for iterative sessions. If you've tried both in a CLI/terminal environment, what's your take? Does Sonnet hold up for deep reasoning and long-chain planning, or does Opus still edge it out there?

For complex workflows, would you recommend switching? Experiences appreciated!

Which model is likely better as a "professor" if you will. One who understands, corrects me, helps editing work on accuracy, gives writing suggestions, etc.

Curious to know what is other's experience using these models? I feel like even with Max plan, i am forced to use Sonnet 4.5 - but holy fuck it's stupid compared to Opus 4.1, it's a fucking moron, cute and funny one, but its IQ can't be above 70. Nevertheless, at least he's a great little coder, when u tell it what to do and test its results comprehensively.

Do you use Opus or Sonnet, and why? Any tips/tricks that makes Sonnet smarter?

They consistently state: We recommend switching to Sonnet 4.5, which now offers: Better coding performance than Opus 4.1

I'd like to see a vote or get a sense of what people are seeing in real situations.

I feel like still get far better results from Opus.

Thoughts?

Hi all - long time Claude & CC user.

Have had only positive things to say about the product so far, Claude Code in particular. The Anthropic team have built an incredible tool that has fundamentally changed my day-to-day as an engineer. My experience is as a Max x5 subscriber and I work on a large, well established code-base.

Just a bit of commentary on my experience with Opus 4.5 for Claude Code and am looking for some feedback from others on their experience so far. I hesitated to make this post, as I think there can be a bit of a tendency to pile-on and not give the team time to resolve issues.

In the early days, I was a heavy Opus user. Would often hit session limits, but usually not too long before the refresh so only typically waiting about an hour. For the cost, waiting this length of time was fine. The introduction of stricter limits, including Opus and weekly didn't affect me even though I use near-daily and often across 3 sessions in a day. I found Sonnet more useful, basically have never hit a session limit, and not once have hit a weekly limit. This has been, for me, a perfect workflow for sometime. Sonnet 4.5 has to be my favourite model to date - context seems large, it always knows where to look, where to edit and does it all unbelievably quickly.

I am not having a similar experience with Opus 4.5. I know it has been a day, so I might be saying this too soon, but my worry is that this model is an 'Opus' only in name. The structure and language of my prompts don't seem to resonate with Opus in the same way as Sonnet. Just this evening I've gone around in circles trying to feed logs from a server to validate a recent change. Opus stood no chance. It was explaining: the concept of logs to me, the structure of the endpoint, the endpoint itself, when the endpoint should be called. I change models, to Sonnet, and ask it to simply 'try again', it validates, finds the issue and presents me the change I was after.

I'm sure, as with all models before it, I'll get use to this one eventually too. I would love to know if anyone is facing similar issues or if they have any tips particularly for large codebases that have helped Opus 4.5 succeed.

How are people genuinely praising Claude Code Sonnet 4.5? I have no idea what’s happening…but from my experience it’s pretty disappointing. Sorry if that stings, but I’m honestly curious about what others see in it.

I’m speaking as someone who uses Claude Code daily easily 7+ hours per day and who has been deeply involved with it since the beginning. I consider myself a power user and truly understand the capabilities it should have. Maybe I’m missing something crucial here…but BESIDES that point I’m really dissatisfied and frustrated with Anthropic right now.

On top of that, the marketing hype around Sonnet 4.5 feels like the same garbage AI slot promotion we saw everywhere with ChatGPT lol. It’s being marketed as the “best model in the world,” likely to people who barely even scratch its surface.

I’ve also just hit a usage limit on Opus 4.1. I’m on the max 200 plan and now there’s some kind of cap in place…for what, a week? Why? If Sonnet is sooooo good why are they placing weekly limits on opus 4.1? So stupid. Can someone explain what’s going on here?

Hi,

after the rate limit shock, opus 4.1 is not affordable anymore - for me at least. In all of my (large) projects, opus 4.1 is doing a lot of better than any sonnet.

Anthropic wrote: Sonnet with extended thinking is better than opus 4.1.

In my experience, thats not true. It lasts longer to get the same (or nearly the same) result with Sonnet - I need to have more prompts. (I am not talking about easy things - the model needs to check several files, needs to understand the whole project etc.)

So my question is: Is Anthropic right and I am doing it the wrong way? Have I overseen something?

Yes, I have turned on the extended thinking in ~/.claude/settings.json:

"alwaysThinkingEnabled": true

Maybe sonnet 4.5 needs another CLAUDE.md than opus?

I read that its possible now to set includes in CLAUDE.md - maybe the best practise has changed here?

So what is your experience? Any tips?