Buddy list is better in Xbox live than it would be on PC, ever. Can always see what your buddy is playing, whether they are on or not, can send invites without leaving the game, and can join right into their game. With PC, you message them, wait for a reply, then try to connect with them. On Xbox Live, every single person is on the same program, and PC can't match it.
Also, everyone who plays has the ability to use voice chat, and most do. On PC, it's an option, but not everyone uses it. Better to talk to all of your team, than half.
Though, PC is better is every other case
