Ask HN: Is Opus 5.5 another step change?

This feels like another moment, like earlier this year, and the year prior. I am thrilled for my use cases in the applications that I build with CC, and for the LLM API usage that I sell. However, it honestly scares the crap out out of me.

Is "the exponential" an actual thing?

10 points | by consumer451 19 hours ago

14 comments

  • jryan49 5 hours ago
    I have Opus 5.5 running subagents for the last 20h without any input from me after developing a plan and it seems to be going well somehow... but I will find out soon...
    • MoneyLovesSpeed 3 hours ago
      20h with no input is insane

      at that point the hard part is just trusting it didnt quietly go off track somewhere imo

      • jryan49 4 minutes ago
        I've been checking it and it's doing great I'm sure there are some bugs but it's doing a huge bulk of tedious simulation logic for my game
  • A_D_E_P_T 18 hours ago
    Yes, Opus 5.5 and Astra-6 are big improvements over Opus 5 and Sol-5.6. I'm at a point where I can automate much of my workflow, even for complicated tasks, which I could never do before.

    Also the new Xiaomi model, Mimo v2.6, is outstanding as a light and cheap model. For coding, the new meta is using Astra-6-Max for orchestration and architecture, and Mimo for grunt work.

  • KellyCriterion 4 hours ago
    First of all, I consider it very expensive, somehow in the range of Fable:

    I activated Opus 5.5 when the invitation popup showed up, and Im already paying as a pro-user - nontheless the usage of Opus 5.5 charged massivly additional on the last few days, around 12-13 USD per day.

    Im still fine with Opus 4.6 or 4.8 for daily development.

  • nr378 17 hours ago
    Yep, I'm personally finding Opus 5.5 to be the first real leap I've felt since Opus 4.5. The time-to-first-token seems dramatically better in Claude Code compared to Fable 5.1/Opus 5 as well, which really helps both interactivity and also overall time-to-completion.

    It also burns Claude subscription quota much more slowly than Fable, which is nice.

  • tkgally 16 hours ago
    I’m also finding Opus 5.5 to be a significant advance. In the past few days, I’ve given it several complex tasks related to two long-term dictionary-building projects [1, 2], and it handled them impressively—similar to Fable but with much lower token consumption. It also communicates better than Opus 5.1; I don’t think I’ve seen any obvious Claudisms yet.

    [1] https://www.tkgje.jp/

    [2] https://tkgally.github.io/eex-dict/index.html

  • JojoFatsani 14 hours ago
    I just love that it knows how to form its thoughts into meaningful statements without rambling again.
  • sznio 11 hours ago
    It's the first model that I feel I can just use freely without crashing into the 5 hour limits. I just manage to get my work done and still have tokens left over
  • brianwawok 16 hours ago
    Feels like a faster and cheaper fable, which yes is a big jump.
  • smnplk 17 hours ago
    yea, apparently you dont need to know Rust
  • moomoo11 3 hours ago
    astra on ultra still blows it out of the water
  • grim_io 17 hours ago
    It's less shit, so that's good I think.
  • m4rtink 17 hours ago
    No. Next question ?
  • sur_lal 5 hours ago
    [dead]
  • kylehotchkiss 14 hours ago
    [dead]