Sorry but GTA 5 pisses all over WD.World immersion (for a sandbox game) and density of the world itself. So many sandboxes go for big and sacrifice detail, I quit GTA after playing San Andreas because of that.
WD is good in that it gives the impression of freedom and life going on in a big city but the reality is everything in the game is carefully scripted, everything is carefully layered to make it look like you are having an effect but the reality is it a pre programmed routine that is running.
Ever wondered why when you hack traffic light it always causes a smash, because the game has been programmed that way. It isn't freedom or interaction it's scripted.
GTA 5 on the other hand, stand at a traffic light pull a gun and fire at a random vehicle. Cars and Peds will start running and driving like mad, sometimes they will smash in to each other and create that wonderful effect you see every time you hack a traffic light in WD and sometimes they will just get away at high speed. That's immersion. Doing something random and not knowing what will happen as a result and it is something WD fails hard at because I know that if I do action A it will lead to action B. Where as in GTA 5 I could do action A and before I know it I am in a gang shoot out with a police chopper overhead and the innocents driving like maniacs trying to get away.