Archtkd
3rd Black Belt
I agree that angles are great way to use roundhouse in sparring.
I believe in self defense, however, which was the situation specified, I prefer the
K.I.S.S. principle.
I don't want to turn this into what kick is better than which, but I get the feeling that you've little appreciation for the efficiency and power of a roundhouse kick, when thrown by someone who knows what they are doing.