"Whether you do a square or oval circuit you still have to turn so its the same problem on a high wing a/c. whatever shape circuit you do you still have to do the same amount of turning to end up on finals!!!"
Hardly true,whatunion. It is the 'time spent blind' which matters. A slow turn to downwind in an 'oval' circuit means that the circuit direction will be obscured for far longer under a high wing than it would be for two quicker 90 deg turns in a 'square' circuit. Whereas in a low wing aeroplane it won't be. So a circuit which will accommodate both configurations will be 'safer' if it's rectangular.
But I far prefer a tight racetrack circuit (or 'oval' as it is wrongly termed)!