Not necessarily... if set up properly with an overflow box, it works the same as one drilled on the side of the tank. It's the difference in having a full length overflow box in the tank, or a smaller overflow box up at the top. No matter how its set up, the tank should not overflow water when the pump is off.
One thing with the bottom drilled tanks is that you can also bring your returns up through another hole, reducing the amount of things behind the tank.
"What, exactly, is the internet? Basically it is a global network exchanging digitized data in such a way that any computer, anywhere, that is equipped with a device called a 'modem', can make a noise like a duck choking on a kazoo." - Dave Barry