It depends on the goal. Given powerful tools, Opus 5.5 will eventually get the job done, but it might have to write/test its own custom software to get there. If you're running the same task thousands of times that's you want to move that work into the harness (building the right tools, right instructions, right guidance). Once you move it into the harness, you probably no longer need Opus, since the hard parts were pre-compiled into harness.
So for 1-off tasks: use smart model and powerful harness (bash + vm). For repeated tasks used optimized harness, and the cheapest model you can get away with.
So for 1-off tasks: use smart model and powerful harness (bash + vm). For repeated tasks used optimized harness, and the cheapest model you can get away with.