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

Execution · Pure Mechanics
Fast arena-style shooter mixing a scripted Strogg campaign with twitch multiplayer.

Execution · Pure Mechanics
Free-to-play military shooter mixing class-based PvP with co-op missions.
Quake 4 leans Execution (Pure Mechanics); Warface leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Quake 4
Aimbot plus strafe-jump inputs dominate both campaign and multiplayer
Warface
Aimbot dominates gunfights; recoil control and flick aim decide duels.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Quake 4
Multiplayer duels reward predicting human positioning and timing
Warface
Human PvP positioning and peek mind-games in versus modes.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Quake 4
Spawn and item timing add mild uncertainty
Warface
Spawn and enemy position uncertainty, minor.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Quake 4
Item control routes and weapon picks are learnable
Warface
Loadout grind and class synergy matter but are mappable.
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.