head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Isometric movement control while herding Flickies along memorised routes.

Execution · Practiced Mastery
Wrangling high-speed 3D movement through fixed stages and boss scripts.
Sonic 3D Blast leans Execution (Practiced Mastery); Sonic Adventure DX: Director's Cut leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic 3D Blast
Isometric momentum control and Flicky herding need precise movement
Sonic Adventure DX: Director's Cut
High-speed 3D control and jank-wrangling demand real hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic 3D Blast
Robotnik bosses run fixed patterns
Sonic Adventure DX: Director's Cut
Chaos bosses run fixed phase scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic 3D Blast
Flicky and badnik placements never change
Sonic Adventure DX: Director's Cut
Stage layouts and upgrades never change
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic 3D Blast
Routing each zone for Flickies and emeralds is learnable
Sonic Adventure DX: Director's Cut
Speedrun routing and A-rank paths are learnable systems
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.