Notwithstanding the political drama surrounding AI, this is the best model Anthropic has produced so far, and I've tried them all - as well as every competitor's. After a couple of 14-hours days spent with it, I'd say it's on par with GPT-6, but at much lower cost. I have $20 subs for both OAI and Claude, and GPT-6 Astra burns my 5-hour credits in an hour or so, where Opus 5.5 lasts nearly all day, as long as I take a proper lunch break. Combined with the I-have-ADHD skill, it's my new daily driver. Opus 5.5 found a lot of major problems Opus 5 had left in my codebase, some of them critical (username and path leaks).