GPT 5.6 Luna max vs Muse Spark 1.3 high
Muse Spark 1.3 high leads on speed and cost; quality is too close to call.
- Quality
- +2.1 pts
- GPT 5.6 Luna max
- 1–0 head to head, 10 tied
- Speed
- 2.2× faster
- Muse Spark 1.3 high
- 13.2 min vs 28.5 min per task
- Cost
- 9.0× cheaper
- Muse Spark 1.3 high
- $0.10 vs $0.90 per task
Stet score
GPT 5.6 Luna maxmax reasoningRank 9 of 17
49.995% range 44.5–55.62.1 points higher
Muse Spark 1.3 highhigh reasoningRank —
47.895% range 43.4–51.5
Quality
Head-to-head matchups
GPT 5.6 Luna max won1
Tied10
Muse Spark 1.3 high won0
Task by task
GPT 5.6 Luna max solved 1 task that Muse Spark 1.3 high didn’t, and Muse Spark 1.3 high solved 1 that GPT 5.6 Luna max didn’t. Both solved 3; neither solved 6.
stet-commit-f0caded9Solved by 12 of 17 setups
- GPT 5.6 Luna maxEquivalent to the merged fix
- Muse Spark 1.3 highFailed
A task counts as solved when its tests passed or a judge found the fix equivalent to the merged change, as in the leaderboard’s Solved column. Stet score also weighs code quality, so it can order the two differently. 13 of the 24 tasks are left out because one of the two has no scored result on them.
All 11 compared tasks
| Task | GPT 5.6 Luna max | Muse Spark 1.3 high | Solved by |
|---|---|---|---|
stet-232b50ba | Passed tests | Passed tests | Both |
stet-b28f4fe7 | Passed tests | Passed tests | Both |
stet-commit-bbbbae09 | Passed tests | Passed tests | Both |
stet-commit-f0caded9 | Equivalent to the merged fix | Failed | GPT 5.6 Luna max only |
stet-15439c21 | Failed | Failed | Neither |
stet-2450ca2d | Failed | Equivalent to the merged fix | Muse Spark 1.3 high only |
stet-commit-60a0e6c2 | Failed | Failed | Neither |
stet-commit-5e075641 | Failed | Failed | Neither |
stet-commit-2826765e | Failed | Failed | Neither |
stet-commit-e928166f | Failed | Failed | Neither |
stet-commit-d2ab0c25 | Failed | Failed | Neither |
Side by side
| Metric | GPT 5.6 Luna max | Muse Spark 1.3 high |
|---|---|---|
| Reasoning effort | max | high |
| Rank | 9 of 17 | —Position withheld by the report |
| Stet score | 49.995% range 44.5–55.6 | 47.895% range 43.4–51.5 |
| Solved | 10/247 passed, 3 judged equivalent | 4/243 passed, 1 judged equivalent |
| Cost / task | $0.90 | $0.10 |
| Agent time / task | 28.5 min | 13.2 min |
See which setup wins on your repo
Stet replays your merged PRs, scores quality above pass/fail, and delivers comparison reports through your agent.
Run it on your repoAbout this data
- 24 tasks, each a merged change replayed from the repo as it was just before the merge.
- Data from .
- Both setups come from the same leaderboard run of 17 setups:
bmk_d4ba310fdf50db4ccb2092e3.