Well Break Points and Overdrives are still a little confusing to me. They are or can be just as powerful as any Materia gained attacks, at least I know Omnislash can be (well, not quite KotR Materia, but still very very strong). Is there a limit on their capabilities of using these attacks?

If it were up to me, Cloud would just Omnislash the shit out of everyone everytime he attacks, for he has no better offensive move, in my opinion.