According to our measurements this isn't true. We re-ran Opus 5.5 today on the benchmark we ran in September, with the same prompt and settings. Before and after, side by side: https://playcode.io/blog/macbook-svg-benchmark#reruns

  Opus 5.5, one MacBook in SVG   Sep 22-23                  Nov 9
  max, streamed (128K cap)       128,000 tok, $2.56, empty  128,000 tok, $2.56, empty
  max, Batch API (300K)          255,957 tok, $2.56         243,707 tok, $2.44
  xhigh                          86,096 tok, $1.72          107,333 tok, $2.15

The Batch API bills half price. Max ran out of the 128K ceiling again, to the token. Given 300K, it drew the same kind of laptop with 5% fewer tokens. Xhigh used 25% more and drew the same kind of laptop. That's inside the noise: 17 identical calls at high ranged from 17,757 to 59,705 tokens.

The model is still the best of everything we've tried. Most likely the next best would be Fable 5.2. But we don't like Fable because essentially the result is the same, just the price is higher. Its medium and high are close to what Opus 5.5 Max had, but the price is higher.

(I run Playcode, an AI app builder. We benchmark every model before we add it.)