no he's right.i have perfectly good connection, still the ps3 manages to make me lag. then when my friend brought his xbox over not even a blur of lag. the ps3 needs faster servers and a lot more.
I think it depends on what game your playing. Sometimes some games have crappy servers while others have fantastic servers. Servers have to be maintained. XBL is just P2P so I dont really think maintaining servers is an issue. You could also have a crappy wireless signal, someone is downloading/torrenting/etc. somewhere else in your home, or it's just your ISP itself.
Yes it's totally dependent on your internet provider/hub. In some area's there are very bad signals. I'm very fortunate my internet runs at 54 Mbps but it does have it's moments. Same goes to the XBOX 360, it's not the console.