I write a lot of Rust and Lean, Fable 5 is in my experience better at both. Cost/performance is a different story.

Fable has become my go to in Agda as well. It just crunches hard technical tasks!

I find Fable 5 still lacking in library design. But I guess there is no accounting for taste…

Yes, both of which are domains for which a verifier is readily available.

You can generalize from them to "science".

This is really it imo. Fable 5 is better then Sol. But Fable is just of the table for anything even remotely long running. Unless you have very deep pockets. And the difference between Fable and Sol is not world shattering if you ask me. I also find codex a ton better than claude.