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 · Practiced Mastery
Arcade car control at speed over memorised tracks with scripted police pressure.

Execution · Pure Mechanics
High-speed trick execution along optimised lines down fixed mountains.
Need for Speed: Hot Pursuit 2 leans Execution (Practiced Mastery); SSX leans Execution (Pure Mechanics).
SSX leans a little harder on execution, though the gap is small.
Need for Speed: Hot Pursuit 2
High-speed cornering and traffic dodging are the whole test
SSX
Trick timing, landings and line control at speed are everything
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Need for Speed: Hot Pursuit 2
AI racers and cops follow rubber-band scripts
SSX
Rival AI racers are aggressive but mappable
Need for Speed: Hot Pursuit 2 leans a little harder on variance, though the gap is small.
Need for Speed: Hot Pursuit 2
Cop spawns and traffic add mild run-to-run noise
SSX
Courses are fixed once learned
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Need for Speed: Hot Pursuit 2
Track knowledge and racing lines are learnable and fixed
SSX
Optimal trick lines and shortcut routing maximise score
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.