Boy oh boy, GTA 5 looks incredible. It's everything I wanted from GTA 4. Amazing graphics, a tightly woven plot with multiple playable characters, a HUGE map to explore, more accurate driving physics (cars appear to actually stick to the road when driving at high speeds). Wow! Can't wait till 2013!
I love GTA 4, but the driving can be a bit clunky at times. Cars do barrel rolls more often than Fox. Granted, GTA 4 was a huge improvement over the PS2 games, but Liberty City didn't have much to do outside of the story.