but how true is this? this is almost impossible to measure and those that do[1] find no significant difference
i personally haven't noticed any downgrade at all.
it's entirely possible there's a mass delusion going on where everyone gets wowed by 4.6 initially, then accepts the new baseline and gets used to it, then thinks that baseline is no longer impressive and thus degraded
it doesn't help that anthropic changed defaults for its claude code harness for all users suddenly
the best and only evidence i've seen for actual degradation is that the web version of opus 4.6 failed the car wash test, and since you cannot simply choose to "disable adaptive thinking" and other parameters with the web version, you truly may have gotten a worse product
i personally haven't noticed any downgrade at all.
it's entirely possible there's a mass delusion going on where everyone gets wowed by 4.6 initially, then accepts the new baseline and gets used to it, then thinks that baseline is no longer impressive and thus degraded
it doesn't help that anthropic changed defaults for its claude code harness for all users suddenly
the best and only evidence i've seen for actual degradation is that the web version of opus 4.6 failed the car wash test, and since you cannot simply choose to "disable adaptive thinking" and other parameters with the web version, you truly may have gotten a worse product
[1] https://marginlab.ai/trackers/claude-code-historical-perform...