Opus 5.5 vs GPT-6 Astra on the same frontend task
Given the same chat-tab optimization task, Opus cut tab highlight from 130-200ms to 8ms, while Astra didn't speed up switching but fixed an unrequested composer flicker and admitted Opus was better at tab responsiveness.
I gave Opus 5.5 and GPT-6 Astra the same task: "Make horizontal chat tabs open and switch faster, and simplify their rendering and initialisation." The results were not what I expected. Opus went straight for what I asked, and switching tabs now feels instant: > Tab highlight: 130–200ms → 8ms > Content visible: 16–25% faster on every switch It also got rid of the flicker on the tab strip, and says streaming got 38% faster along the way. Astra took a different path. On the same benchmark, tab switching didn't get faster, and two of the three switches actually got slightly slower. But it fixed something I never asked for: the composer used to blink every time you changed tab, and now it doesn't. The funny part is that Astra admitted it in its own summary: "Opus is better for tab responsiveness." In the end I combined both: Opus's tab speed plus Astra's composer fix. But the takeaway from this experiment is clear. Opus seems much better at understanding the intent behind a prompt. Astra did good work, just not the work I asked for.