"The game doesn't seem to look any better than GTA IV on PS3 and I don't want to feel like I'm playing yet another GTA IV expansion pack for the coming years."

Your judgment of the value of a game is purely how it looks? That sounds very destructively reductionist.

GTA V shares literally nothing with GTA IV -- different character, location, dynamics, physics, storyline, music, voice actors, etc, but because it's people and cars that makes it an expansion pack?