head to head
World of Warcraft asks more than Guild Wars 2, and the gap is optimization.

Optimization · Practiced Mastery
Active dodge-heavy combat with a deep build system, tested against both scripted content and human opponents.

Optimization · Pure Optimization
An MMORPG dominated by theorycraft, gear math, and rotation execution.
Guild Wars 2 leans Optimization (Practiced Mastery); World of Warcraft leans Optimization (Pure Optimization).
Guild Wars 2 leans a little harder on execution, though the gap is small.
Guild Wars 2
Dodge timing and active combat define moment-to-moment play
World of Warcraft
Rotation APM and mechanics matter in raids
Guild Wars 2 leans a little harder on reads, though the gap is small.
Guild Wars 2
WvW and structured PvP feature real adaptive opponents
World of Warcraft
PvP arenas have light read element
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Guild Wars 2
Loot RNG is present but secondary to skill expression
World of Warcraft
Loot tables and crit RNG present
World of Warcraft leans clearly harder on optimization.
Guild Wars 2
Build crafting and rotation theory-crafting reward deep analysis
World of Warcraft
Gear, talents, and rotation are mathematically solved
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.