What benefits should we expect from the 3-4 switch?

Obviously we want the defense to be "better"......but we've had "better" defenses with the 4-3 as well. In fact, pretty much every defense in the history of defenses was better than what we saw last season.

More specifically, what benefits should we expect, from a schematic standpoint, by switching to the 3-4? Will our personnel be better suited for it? Will it hide weaknesses of some of the players that may otherwise be glaring in a 4-3? Will it lead to a better pass rush?

Would love to hear everyone's take on this.