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

Optimization · Pure Optimization
A turn-based JRPG won by persona fusion and social-link routing.

Optimization · Pure Optimization
A calendar-driven JRPG carried by persona fusion and social-link planning.
Persona 3 Reload leans Optimization (Pure Optimization); Persona 4 Golden leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 3 Reload
Turn-based, low input demand
Persona 4 Golden
Turn-based, no input demand
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 3 Reload
Scripted enemies and bosses
Persona 4 Golden
Scripted enemies
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 3 Reload
Weakness, crit, and fusion rolls
Persona 4 Golden
Weakness and crit rolls
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 3 Reload
Persona fusion and social link routing central
Persona 4 Golden
Persona fusion and calendar routing rewarded
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.