Center channel question

Regarding the distance, the angle and the axis from the listener, which CENTER channel is better and why? The one with 2 woofers and 1 tweeter in the middle or the one with 1 woofer and 1 tweeter? We can assume that they have the same frequency range and the same power. The only difference I can see is that the first one (dual woofer) disperses a more symmetrical sound but I can be wrong. Also why the second one (single woofer) is often seen with bass vent (1 or 2 reflex ports)?