ElevenLabs is strong for audiobooks: studio-quality voices, workable pacing via explicit pauses/newlines and per-voice settings, and viable bulk processing through the API (batch scripts + cost/rate-limit planning). SSML support is limited—rely on punctuation/pauses and test long passages. Expect a light human pass for intonation and chapter flow; run a pilot chapter to validate quality and cost. Try a pilot via ElevenLabs.