1) FFXIV's rain/weather effect is one of the best i've seen in a game thus far. It orientates itself to the camera and reacts accordingly to being indoors/outdoors.
2) FFXIII-2's rain filter was garbage. It looked like perpetual static, something i could not get my eyes to un-see once i noticed. OP should be ashamed of himself.
3) The rain effect wasn't changed. They just added "wet" shaders to the materials.