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

Execution · Pure Mechanics
VR rhythm game about slicing color-coded blocks to music with lightsabers.

Execution · Pure Mechanics
Sequel rhythm game with harder setlists and refined plastic-guitar technique.
Beat Saber leans Execution (Pure Mechanics); Guitar Hero II leans Execution (Pure Mechanics).
Beat Saber leans a little harder on execution, though the gap is small.
Beat Saber
Pure full-body rhythm precision at speed
Guitar Hero II
Harder charts, hammer-ons, and three-note chords
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Beat Saber
No opponent of any kind
Guitar Hero II
Static note highways
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Beat Saber
Patterns are fully known and fixed
Guitar Hero II
Fully deterministic charts
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Beat Saber
Swing-angle scoring technique and map memorization
Guitar Hero II
Star power pathing for leaderboard play
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.