Anecdotal, but I have the model write a podcast script of two reviewers talking about a book, one chapter at a time.

Fable (5.1 and 5.2) consistently write a much shorter script (2.5 pages) compared to Opus 5.5 (4.5 pages).

Fable 5.2: https://claude.ai/share/274a96a8-c8a5-4564-9ca1-e914edffc722

Opus 5.5: https://claude.ai/share/da8ab6bd-0987-47dc-9c26-68ebbfb25781