... between natural dialogue and awkward pauses. These models are often architected for immediate response but may sacrifice some prosodic quality for speed. High fidelity models like Dia 1.6B and Coqui XTTS take the opposite approach: processing entire text passages to optimize for naturalness, emotion, and overall speech quality. They're ideal for content creation, audiobook narration, or any application where the extra processing time translates to noticeably better output quality. This architectural difference explains why you'll see such ... ... responsiveness users experience. For context, human conversation typically has response delays under 200ms, so TTFB figures above this threshold start to feel unnatural in conversational AI. However, TTFB only tells part of the story: total processing time for longer passages