For ordinary coding (making webapps, frontend and backend), the non-SOTA models do fine, but the SOTA models have better judgement and need me to intervene less often, allowing workflows like "Go and pitch me a solution to this problem, then go build it". 6 months ago, I would give lower-level tasks and read more of the code myself.

So I don't "need" the SOTA models, but they do help considerably. And I am also working on some other projects that may have been outside the reach of the earlier models entirely.

Subagents are a godsend. Frontier models for initial planning and spec writing, cheaper models for implementing from the spec, frontier models for review. Frontier models to help with research. The availability of cheaper models is great, since it gives more price points for different tasks.