Opus 5.5 Ports HAProxy 51% Cheaper Than Fable 5.1, Winning Back Codex Converts
every · x · 2026-09-23
Every's team published a hands-on test of Opus 5.5: tasked with porting HAProxy from C to Rust, both Opus 5.5 and Fable 5.1 passed nearly all tests, but Opus 5.5 finished in 9.5 hours vs 12 hours, at 51% lower cost.
Reactions were largely positive: Kieran Klaassen made it his daily driver, and former Codex switchers Mike Taylor and Tyler Nishida are reconsidering — Nishida said his "jaw dropped five or six times this week."
Caveats remain: Dan Shipper calls it a "smaller Fable" — great for large end-to-end coding projects, but he still prefers the Codex harness and OpenAI models for knowledge work; its writing can bury the point and it overreaches on simple tasks.
Related event: Opus 5.5 Ports HAProxy C to Rust, 2.5 Hours Faster and 51% Cheaper(2 posts)→
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