I was playing GTA V on PS3 yesterday/today for a few hours. Game is incredible, map is enormous - i am happy as it is. Will take you lot of time to discover what the game offers for sure. Car driving is different - i don't know if it's worse or better. It is different - and as for now I'd preffer GTA IV style.
Walking up the highest mountains will take you around 20 minutes. You can meet tourists, they are eating, drinking, resting, reading map, watching wild life. You can hear a wind, you can hear the birds or even small insects hidden in the grass. You can feel that the world is alive and that you are a part of it. It's incredible experience. Everything is colorful, people are living their life. Contrast between 3 progs is stunning. Everything will make you say "wow" when you see it for the first time.
It's awesome how I see places from screens and trailers while driving/walking in-game. It's been a long journey, now we're home. And the journey was worth the effort.
Now it's time to wait for PC version and in the spare time I will play it from time to time with my friend on PS3.