carb. mounting shape?

[bc]

There are many different shapes out there now for the carb. mounting flange, there is the standard square shape, cloverleaf style, round, oval and others. Is there really any power or flow advantage from one style or shape to the next? I have an intake that is the cloverleaf style but most of the spacer out there are spuare so I have thought about changing my intake to the square style so I can test different spacers but would doing this cause a loss of power?