Pro and cons of different styles of over flows

[The Guy]

I drilled 2 holes in the back at the top of my 90 g and used an internal 1200 gph overflow.
Bought it from BRS 12"x6"x6" and installed it as per their instruction video, going do the 1" herbie drain with a redundent emergency 1" drain. Return from the sump will be back into the tank over the rim.