Overflow placement - 1 vs 2 returns?

[Myka]

I have similar views of the bean animal as Albert does. I'd use the center hole for the return. I prefer side overflows to center overflows, but as Brad suggested, sometimes your plans change and the side overflow would become viewable.

[Snappy]

I would go with it centered and make it external if possible.

[maron6977]

I have a 4' 120g . Dual overflows , not in corner & I hate it !
My choice would be corner overflow , run the overflow at 45 degree angle .
Just my $.02