opus 5.5 is cheaper to serve than opus 5 and since it can match or even beat fable at coding for less compute, more people are using the smaller model if fable 5.5 is as good as rumored anthropic will serve even more users with less compute which should help ease its capacity constraints

opus 5.5 is the perfect combination of usage and quality it has an amazing intelligence-to-cost ratio. sure it gets things wrong more often than fable would but the cost savings are worth it fable 5.5 needs to be something truly special to justify the higher usage consumption

opus 5.5 and astra are good at different things openai already seems ahead on cyber capabilities and the fact that 6.1 Astra was shelved over safety and alignment concerns makes me wonder just how capable its next models are getting meanwhile anthropic gotten better at shipping frontier models safely while still moving faster than oai

Opus 5.5 seems to have quietly gotten worse. On top of usage limits draining ridiculously fast, the quality of its outputs now seems to be dropping too. I've been getting a lot of comments about this, and I've seen several other posts reporting the same thing. It's starting to look like a widespread issue. My guess is that Anthropic has been tweaking the harness or checkpoint so much that they ended up breaking something along the way.

Opus 5.5 + Jig + Cleaning windows with my daughter. “Best way to use a squeegee on this sliding door”, photo of door, out comes a Jig with a fully interactive cleaning step 😂 I was hoping it would do that!

opus 5.5 and astra are quite different on SWE tasks astra has a much higher floor while opus has occasional spikes with a higher ceiling but astra's reasoning is in a tier of its own. you can throw almost anything at it even problems it hasn't encountered before and it'll find a way to figure things out

opus 5.5 dropped on september 22, so it wouldn't be surprising if Fable 5.5 follows in late october openai will probably release Astra 6.1 around the same time, either just before or after fable 5.5 at this point, major new releases are dropping every 2–3 weeks on average