head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Optimization · Pure Optimization
Sci-fi thriller played as the station AI solving its own crisis.

Optimization · Practiced Mastery
A deadpan janitor sim about mopping up the gory aftermath of sci-fi shooter battles.
Observation leans Optimization (Pure Optimization); Viscera Cleanup Detail leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Observation
Camera control and interface manipulation
Viscera Cleanup Detail
Mop physics fumbling, lightly fiddly at most
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Observation
Events are fully authored
Viscera Cleanup Detail
Nothing opposes you
Observation leans a little harder on variance, though the gap is small.
Observation
Mystery unknown until uncovered
Viscera Cleanup Detail
Messes are placed, not random in any meaningful way
Observation leans a little harder on optimization, though the gap is small.
Observation
Systems puzzles and station schematics solving
Viscera Cleanup Detail
Efficient cleanup order and bucket logistics are the game
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.