Edit: also, death from above > mortar strike and force lightning > pebbles, etc.
DFA and Lightning definitely look cooler, but the mortar strike and pebbles animations are stealthier making it a little more challenging to find the source thus giving the casters a slight advantage in PVP.
As for the topic at hand, I found personality differences in players in WoW back when it first came out. Horde players we're definitely kinder and more helpful. Not sure if it's still that way or not though.
I don't see any personality differences in players in SWTOR however.