No, I don't think it is a better game than D3, the one big thing POE has is more depth. That does not make it a better game, for some replayability is key to a great game, for others it is the actual gameplay, graphics & story or a multitude of other things.
For me D3 will be looked at with a great deal of fondness by people in years to come, it just lacked depth. I think they did not invest enough resources into endgame. Hoping that D4 is dark and from what i have seen so far looks great.