I don't play a lot of xbox live so I can't really give it the edge without playing more games online. I will say this though:
The fact that there's no way to play online/local mixed with Worms 2 Armageddon or Castle Crashers (Castle Crashers lets you but you have to use a level 1 character!) makes no sense whatsoever. I'd trade half the xbl bullet points that xbox fans have listed in this thread so I could do mixed local/online in those two games.
Though I only have experience with these two, I suspect there are others with rubbish local/online mixed compatibility. This is completely inexcusable for a premium online service and I hope it's some fault of the developers and not some forced restriction on online play without a gold account.
Demon's Souls Official Thread | Currently playing: Left 4 Dead 2, LittleBigPlanet 2, Magicka