Guild Wars 2

…between a full cast Meteor Shower and a half-one?

The AoE starts pretty much around 40% of the cast, so what does the rest 60% do, if anything? What gives?

The duration of shower

The meteor show last after the cast if cast for full duration. Otherwise if you break it halfway it will not last as long. This is the same for rangers longbow 5 aoe cripple move and allows the move to be interrupted if you can find the caster

The number of meteors that come down is significantly less if you cancel it early.

I don’t know why all of you keep saying it’s the duration. It lasts around 13 seconds whether or not you cancel it early. Test it for yourself with “Show Skill Recharge” enabled.