I won't copy and quote you guys but posts 41 and 43 were both excellent!
You are both so right and everything you said was true.
Yes, usually pulling a weapon of any kind will result in an attacker rethinking where he is supposed to be at the moment.
Perhaps a bigger round will stop someone better, but it also depends on shot placement.
Where am I going? Right where posts 41 and 43 were. Is the .380 effective? Depending on which parameters you judge it on, I'd give it a conservative yes.
But then so are the .22, .25 and .32.