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GPT 6 Luna low vs Muse Spark 1.3 high

No clear quality winner: Muse Spark 1.3 high won 12, GPT 6 Luna low won 4, 7 tied, 1 undecided; GPT 6 Luna low leads on cost and agent time: 1.9× cheaper and 1.9× faster.

24 tasksData from

Stet score

GPT 6 Luna lowcodex · low reasoningRank 16 of 16

19.995% range 11.6–29.5

Muse Spark 1.3 highmuse · high reasoningRank 14 of 16

31.995% range 23.5–40.612.0 points higher

A directional read: their 95% score ranges overlap.

Cost / task

GPT 6 Luna low$0.051.9× cheaper
Muse Spark 1.3 high$0.10

Agent time / task

GPT 6 Luna low6.9 min1.9× faster
Muse Spark 1.3 high13.2 min

Quality

Head-to-head matchups

GPT 6 Luna low won4

Tied71 undecided

Muse Spark 1.3 high won12

Muse Spark 1.3 high’s win share 66%, 95% range 49–81%Ties are within judge noise.

Task by task

GPT 6 Luna low solved 1 task that Muse Spark 1.3 high didn’t, and Muse Spark 1.3 high solved 6 that GPT 6 Luna low didn’t. Both solved 4; neither solved 12.

GPT 6 Luna low only 1

  • stet-15439c21Passed tests

Muse Spark 1.3 high only 6

  • stet-5276aa3fPassed tests
  • stet-commit-bbbbae09Passed tests
  • stet-66762b4cPassed tests
  • stet-commit-5d766ddeEquivalent to the merged fix
  • stet-43493c52Passed tests
  • stet-2450ca2dEquivalent to the merged fix

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. 1 of the 24 tasks is left out because one of the two has no scored result on it.

All 23 compared tasks
Task by task
TaskGPT 6 Luna lowMuse Spark 1.3 highSolved by
stet-3169aefaPassed testsPassed testsBoth
stet-89dfbc27Passed testsPassed testsBoth
stet-b28f4fe7Passed testsPassed testsBoth
stet-232b50baPassed testsPassed testsBoth
stet-5276aa3fFailedPassed testsMuse Spark 1.3 high only
stet-commit-bbbbae09No change madePassed testsMuse Spark 1.3 high only
stet-66762b4cFailedPassed testsMuse Spark 1.3 high only
stet-15439c21Passed testsFailedGPT 6 Luna low only
stet-commit-5d766ddeNo change madeEquivalent to the merged fixMuse Spark 1.3 high only
stet-43493c52FailedPassed testsMuse Spark 1.3 high only
stet-commit-f0caded9FailedFailedNeither
stet-6f84e978FailedFailedNeither
stet-2450ca2dFailedEquivalent to the merged fixMuse Spark 1.3 high only
stet-commit-342d0ac0FailedFailedNeither
stet-commit-f8ae1177No change madeFailedNeither
stet-commit-5e075641FailedFailedNeither
stet-commit-2826765eFailedFailedNeither
stet-commit-a8716b88FailedFailedNeither
stet-commit-e928166fFailedFailedNeither
stet-commit-30506f8eFailedFailedNeither
stet-commit-87814583FailedFailedNeither
stet-commit-d2ab0c25FailedFailedNeither
stet-commit-e41c2e2dFailedFailedNeither

Side by side

Side by side
MetricGPT 6 Luna lowMuse Spark 1.3 high
Harnesscodexmuse
Reasoning effortlowhigh
Rank16 of 1614 of 16
Stet score19.995% range 11.6–29.531.995% range 23.5–40.6
Solved5/245 passed, 0 judged equivalent10/248 passed, 2 judged equivalent
Cost / task$0.05$0.10
Agent time / task6.9 min13.2 min

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About 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 16 setups: bmk_d4ba310fdf50db4ccb2092e3.

See all 16 setups on the leaderboardHow Stet measures