I don’t use Haiku for planning of big tasks, so we basically agree on that. But even just Sonnet 4.6, on a fairly large codebase, only truly goes into the weeds maybe 10% of the time for me. I also write pretty specific initial prompts, and have a good idea of how I want the code to work before I start prompting. For example, sometimes I will spend several hours writing a spec before even picking up the power tools.

I have never had the situation you describe, where Opus won’t come up with “a reasonable plan”, but your definition of “reasonable” might be very different than mine, and of course, running through your credit limit is an entirely tangential problem.