The game itself though as originally made for the last generation of consoles, and the new updated game for the Playstation 4 and Xbox ONE is just that...an updated version. Personally I can't tell much of a difference between the two, and in the future I'd imagine that Rockstar would work solely with the current generation of consoles so will be made to look and play a whole lot better.
At the moment for me, even though I do enjoy the game, it still feels as if it's a game that is struggling to be effective on the newer consoles, but again, I think that's simply because it was never intended to be released on the devices we're using now.