It's way better than Opus 4.5. See my stress test elsewhere in this thread (C -> microcode compiler with optimizations written in OCaml, generates microcode + Verilog output) - it's doing better than Opus 4.6/4.8 were when I was using them to code the original C version of this compiler early in the year. It's come up with optimizations that Claude didn't come up with back then.