I'm an Oval circuit (or to give it's proper name, constant aspect circuit) fan myself. It gives better visibility of traffic ahead on finals, is quicker, allows you to reach the right touchdown point more accurately, and reduces the bank angle used in the circuit.
It also lends itself well to separation of traffic flying at different speeds (and sometimes heights) on the same runway.
A run and break, if flown, has to be combined with a constant aspect approach, but the converse is not true. All the same joins used in a rectangular civil circuit can still be flown.
G
[This message has been edited by Genghis the Engineer (edited 24 April 2001).]