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Muse Spark 1.3 high vs Opus 5 medium

No clear quality winner: Opus 5 medium won 15, Muse Spark 1.3 high won 2, 7 tied; Muse Spark 1.3 high leads on cost and agent time: 67.7× cheaper and 1.8× faster.

24 tasksData from

Stet score

Muse Spark 1.3 highmuse · high reasoningRank 13 of 15

32.895% range 24.3–41.6

Opus 5 mediummedium reasoningRank 4 of 15

63.795% range 53.3–73.630.9 points higher

Their 95% score ranges don’t overlap.

Cost / task

Muse Spark 1.3 high$0.1067.7× cheaper
Opus 5 medium$6.78

Agent time / task

Muse Spark 1.3 high13.2 min1.8× faster
Opus 5 medium23.2 min

Quality

Head-to-head matchups

Muse Spark 1.3 high won2

Tied7

Opus 5 medium won15

Opus 5 medium’s win share 79%, 95% range 65–90%Ties are within judge noise.

Task by task

Muse Spark 1.3 high solved 0 tasks that Opus 5 medium didn’t, and Opus 5 medium solved 4 that Muse Spark 1.3 high didn’t. Both solved 10; neither solved 10.

Muse Spark 1.3 high only 0

Opus 5 medium only 4

  • stet-15439c21Passed tests
  • stet-commit-f0caded9Passed tests
  • stet-6f84e978Passed tests
  • stet-commit-2826765eEquivalent 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.

All 24 compared tasks
Task by task
TaskMuse Spark 1.3 highOpus 5 mediumSolved by
stet-3169aefaPassed testsPassed testsBoth
stet-89dfbc27Passed testsPassed testsBoth
stet-b28f4fe7Passed testsPassed testsBoth
stet-232b50baPassed testsPassed testsBoth
stet-5276aa3fPassed testsPassed testsBoth
stet-commit-bbbbae09Passed testsPassed testsBoth
stet-15439c21FailedPassed testsOpus 5 medium only
stet-66762b4cPassed testsPassed testsBoth
stet-commit-5d766ddeEquivalent to the merged fixEquivalent to the merged fixBoth
stet-commit-f0caded9FailedPassed testsOpus 5 medium only
stet-43493c52Passed testsPassed testsBoth
stet-6f84e978FailedPassed testsOpus 5 medium only
stet-2450ca2dEquivalent to the merged fixPassed testsBoth
stet-commit-f8ae1177FailedFailedNeither
stet-commit-342d0ac0FailedFailedNeither
stet-commit-60a0e6c2FailedFailedNeither
stet-commit-5e075641FailedFailedNeither
stet-commit-2826765eFailedEquivalent to the merged fixOpus 5 medium only
stet-commit-a8716b88FailedFailedNeither
stet-commit-e928166fFailedFailedNeither
stet-commit-30506f8eFailedFailedNeither
stet-commit-87814583FailedFailedNeither
stet-commit-d2ab0c25FailedFailedNeither
stet-commit-e41c2e2dFailedFailedNeither

Side by side

Side by side
MetricMuse Spark 1.3 highOpus 5 medium
Harnessmuse—
Reasoning efforthighmedium
Rank13 of 154 of 15
Stet score32.895% range 24.3–41.663.795% range 53.3–73.6
Solved10/248 passed, 2 judged equivalent14/2412 passed, 2 judged equivalent
Cost / task$0.10$6.78
Agent time / task13.2 min23.2 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 15 setups: bmk_d4ba310fdf50db4ccb2092e3.

See all 15 setups on the leaderboardHow Stet measures