Anyone tried Retell vs Bland vs Synthflow for AI voice cold calls?
voice_pilot · 2026-05-09 · 890 views
Adding AI voice as multichannel layer to cold email sequences. Cold email reply → AI voice follow-up. Evaluating Retell, Bland, and Synthflow.
What I've learned so far.
Retell: sub-700ms latency feels natural in conversation. $0.07/min. Developer-first.
Bland: graph-based Pathways enable complex branching. Slightly higher latency.
Synthflow: no-code builder accessible to non-technical operators. Slower latency.
My pick. Retell for low-latency conversational quality. Setup took our dev 2 days. Cold email → positive reply → Retell calls within 15 minutes. Reply-to-meeting conversion up 40% vs email-only follow-up.
Compliance note. TCPA matters for US outbound. Honor DNC registry. Call recording disclosure required.
Pair with pre-warmed inboxes from PuzzleInbox for email infrastructure. Voice adds the channel.