Teamwork! The PS3 does not need party chat. The PS3's focus on the game allows for complex team based games to thrive. It allows me to truly get lost in a single player experience.
I also like the 360 - that it allows for the social experience while playing a single player game and that you can talk only among your friends while playing a multiplayer game.
They are very different experiences that allow for different gaming experiences... but I personally wouldn't trade the complex, team based fun of playing PS3 games for the social aspect of the 360. For me, it would ruin the fun of many multiplayer games.
So please... PS3 gamers - quit whining for cross game chat! We don't need it.
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