My opinion on bragging:
If it's justified, and done with a sense of humor, then it's merely amusing to me.
I'm not too deeply concerned with picking out 'perfect people' in the world. That's a task doomed to failure. If justifiable pride is a person's primary flaw, well, that's harmless enough to be sure.
What DOES put me off? People who find it necessary to spread their negative opinions of others in situations where it's not critical to do so. Those who put down others tend to have a low self esteem, and that can be a far more dangerous personality flaw than a bit of bragging. They put others down to build themselves up, and portray themselves as superior, because they don't feel that they are. ('If I'm bad', they think, 'others have to be worse'). A person with a low self-esteem might do anything...after all, they don't think much of themselves to begin with, so why hold to morality or ethics? That's a person that I am far more cautious around than a braggart.