This is SO wrong.

I actually wrote my own simple agent (with some twists) in part so I could compare models.

Opus 4.5 is in a completely different league to Sonnet 4.5, and 3.7 isn't even on the same planet.

I happily use my agent with Opus but there is no world in which I'd use a Sonnet 3.7 level model for anything beyond simple code completion.