Some of the newer models available on OpenRouter are good, but I agree that none of them are a replacement for Opus 4.6 for coding.

If you're trying to minimize cost then having one of the inexpensive models do exploratory work and simple tasks while going back to Opus for the serious thinking and review is a good hybrid model. Having the $20/month Claude plan available is a good idea even if you're primarily using OpenRouter available models.

I think trying to use anything other than the best available SOTA model for important work is not a good tradeoff, though.