For me, the only metric that matters is wall-time between initial idea and when it's solid enough that you don't have to think about it.

Agentic coding is very similar to frameworks in this regard:

1. If the alignment is right, you have saved time.

2. If it's not right, it might take longer.

3. You won't have clear evidence of which of these cases applies until changing course becomes too expensive.

4. Except, in some cases, this doesn't apply and it's obvious