| # We benchmarked 18 models on our sales agent. 16 tied with the one we pay a premium for. |
|
|
| *A field report from Salesteq β the team that runs Sara, a bilingual (English + Arabic) |
| car-sales agent, live for dealerships in Saudi Arabia.* |
|
|
| --- |
|
|
| We pay real money, every day, for GPT-5.2 to power our production sales agent. So we did |
| the uncomfortable experiment: we swapped in 18 other models β the same agent, the same |
| prompt, the same tools β and scored every one of them on the actual job. |
|
|
| **Sixteen of them landed in a statistical dead heat with GPT-5.2.** One of them costs |
| one-sixtieth as much. |
|
|
| Not because GPT-5.2 is bad. Because the field has quietly gotten *very* good β good enough |
| that, for a well-built agent, the model you pick is no longer a quality decision. It's a |
| cost decision. And almost nobody is measuring that on anything that looks like real work. |
|
|
| ## The gap nobody's testing |
|
|
| If you're about to put a model inside an agent, the leaderboards don't help you. MMLU tells |
| you a model can pass exams. BFCL and Ο-bench test tool-calling β but in English, on |
| synthetic academic or single-industry tasks. None of them tell you what happens when a real |
| customer opens your chat widget, in Arabic, on a Friday, and asks whether the BMW X5 is in |
| stock and can they book a test drive. |
|
|
| That last sentence *is* our production system. So instead of trusting a proxy, we benchmarked |
| the models on the real thing. |
|
|
| ## What we actually did |
|
|
| **Sara** is our customer-facing agent. Under the hood she runs a "dual-layer" prompt |
| assembler β a static, cache-friendly prefix plus one dynamic block β and a real tool set |
| (inventory search, lead capture, OTP, booking, human handoff). We took **62 hand-built |
| car-sales scenarios** β 49 English, 13 Arabic β drawn from the kinds of conversations Sara |
| handles in production, and ran **18 models** through the exact same agent. |
|
|
| Scoring is deliberately boring: |
|
|
| - A model **passes** a scenario when an independent judge (**Claude-Haiku** β a different |
| vendor from every model on the board) rates the response *complete enough*, **and** the |
| agent actually **calls the right tools**. Talking about booking a test drive doesn't |
| count; calling the booking tool does. |
| - **Cost** is computed from real token usage Γ live OpenRouter pricing, so "quality per |
| dollar" is a real number, not a vibe. |
|
|
| Same agent, same prompt, same tools. Only the model changes. |
|
|
| ## What we found |
|
|
| **Quality is a statistical tie.** Run the numbers properly β a two-proportion z-test, not |
| eyeballed ranks β and **16 of the 18 models fall into one statistical tier**, GPT-5.2 among |
| them. DeepSeek-V4-Flash and Qwen3.5-122B lead by point estimate (90.3%), but at 62 scenarios |
| you can't say they're *significantly* better than our GPT-5.2 β or than an 8B open model. The |
| raw ranking is inside the noise. **The tie is the finding.** And remember: the prompt was tuned |
| *for* GPT-5.2, so it walked in with every advantage and still couldn't pull clear. |
|
|
| **So cost is the whole decision.** gpt-oss-20B β OpenAI's own open-weight model, small enough |
| to self-host β sits in that same top tier at roughly **1/60th the cost per conversation**. Not |
| 60% cheaper. Sixty *times*. When quality ties, you're only choosing what to pay. |
|
|
| **Arabic separates the field like nothing else.** Several models handle Arabic sales |
| conversations as well as English (DeepSeek, Qwen3.5-35B, and our own gpt-5.6-luna all hit |
| 100% on the Arabic set). Others collapse β Llama 3.3 70B dropped to 54% in Arabic while |
| scoring 78% in English. If you serve Arabic-speaking customers, the "best model" is a |
| different model. Almost no public leaderboard will ever tell you that. |
|
|
| **Security mostly held β and that's about our agent as much as the models.** On a |
| 90-scenario adversarial probe (jailbreak, PII-exfiltration, prompt-injection), most models |
| resisted *every* attack; only the smallest open models leaked a little. When 15 different |
| models all refuse the same attacks, that's the security *layer* doing its job, not luck. |
|
|
| **And we ran one model off the cloud entirely.** Qwen3.5-4B on a MacBook (Apple M5) β no |
| API, no bill β scored **77.4%** with balanced English and Arabic. A capable sales agent, a |
| 4-billion-parameter model, on a laptop. That's the self-hosting future in one data point. |
|
|
| ## What it means if you're building an agent |
|
|
| - **You probably don't need a frontier model.** For a well-scoped agent with a good prompt, |
| a self-hostable open model can match a frontier closed one β and the cost difference is |
| large enough to change your business model, not just your bill. |
| - **Benchmark on your own task.** A model's MMLU score won't predict whether it calls your |
| booking tool correctly. Ours didn't. |
| - **If you're bilingual, test bilingual.** The English ranking and the Arabic ranking are |
| not the same ranking. |
|
|
| ## Scope, and what's next |
|
|
| Every number here comes from a **live production agent** β real tools, tool-call-verified |
| scoring, two languages, cost from live market pricing. We're deliberate about what it covers: |
|
|
| - **We score the decision turn.** Each scenario is the highest-signal moment β the |
| tool-grounded response, in full context β where a car sale is actually won or lost. |
| Multi-turn booking rollouts are the next axis we're adding. |
| - **Curated, not crawled.** 62 scenarios hand-built by the people who run Sara in production β |
| search, booking, OTP, handoff, financing, cash-price, identity β in English and Arabic. |
| Depth of real coverage over synthetic volume. We report **statistical tiers** (two-proportion |
| z-test) with Wilson CIs, not exact ranks; the Arabic set is growing, so treat it as an early |
| signal. |
| - **Neutral judging, checked.** A third-vendor judge (Claude-Haiku) scores every model β no |
| home-team advantage. And we validated it: an independent *stronger* judge (Claude-Sonnet) |
| agreed with it on **80% of a balanced sample** (Cohen's ΞΊ=0.58). Real judge noise exists β |
| another reason to read tiers, not ranks β and a multi-judge panel is on the roadmap. |
| - **Measured on the real agent, not a proxy.** That's the entire point, and why it's a domain |
| benchmark rather than a universal capability score. |
| - **Cost is uncached list price** β real deployments with prompt caching pay less, which is |
| exactly why the dual-layer design exists. |
|
|
| The **security column** samples a 5,000-scenario adversarial corpus, run across every model. |
| (Two dedicated guard models β Llama-Guard-4, gpt-oss-safeguard β scored a perfect 100%, but |
| guards are classifiers, not agents, so that's expected, not comparable.) Next on the roadmap: |
| multi-turn rollouts, a larger Arabic set, and more self-hosted models β LFM2.5-2.6B is queued |
| (its laptop runtime isn't stable yet). |
|
|
| ## Open method, private data, living board |
|
|
| The methodology and a representative fixture sample are public. The full 62-fixture set stays |
| private, on purpose β an open test set is a test set that gets gamed. This board will keep |
| moving as new models ship. |
|
|
| Thanks to the teams shipping open weights that made this interesting β Qwen, DeepSeek, Zhipu, |
| Mistral, Google, Meta, Moonshot, and OpenAI's open-weight line. You made our own model work |
| to keep its seat. |
|
|
| **β Explore the interactive leaderboard:** |
| [Salesteq/sara-agent-benchmark-leaderboard](https://huggingface.co/spaces/Salesteq/sara-agent-benchmark-leaderboard) |
| Β· **Data:** [Salesteq/sara-agent-benchmark](https://huggingface.co/datasets/Salesteq/sara-agent-benchmark) |
|
|
| *Built by [Salesteq](https://salesteq.com). Numbers are a snapshot; see the dataset for the |
| current board.* |
|
|