"What is the best looking game of the PS3/360 era?" is the question, not which game had better tech. If you think GTA V looks better than Max Payne 3 I don't know what to tell you, GTA V at times is the jaggy capital of the world. Some character models have 2D objects plastered on.
What exactly is the difference? It's no matter to what I think personally if I completely ignore the reality of the things, GTA V art & tech assets is superior to Max Payne 3 because it's an evolution of the same engine, it's not that tough to understand. The rest of your opinion is simply subjective, I have seen the game, it's quite good but it's not even a free roaming & it use exactly the same setting of GTA V, how could beat it?