Verdict
Built from the measurements below
- Accuracy is too close to call: Claude Haiku 5.5 scored 68.8% and MiMo-V2.6-Pro 68.8% on the same 80 questions, a gap within what chance alone could produce.
- Claude Haiku 5.5 is 4.1× cheaper per question as billed ($0.00048 vs $0.002), reasoning tokens included.
- Claude Haiku 5.5 generates text 3.3× faster: 192 tokens per second against 58.
Which should you choose?
Choose Claude Haiku 5.5 for the lower cost per correct answer ($0.0007 against $0.0029), faster streaming and shorter outputs (about 873 tokens per question against 2,157). Choose MiMo-V2.6-Pro for open weights you can run yourself.
Accuracy gap +0.0 points (z = 0.00). We call a winner only when z is at least 1.96, the usual 95% threshold. Speed, latency and price need a 10% margin.