I come from Wii- GST world and we faced a similar problem (a player from Australia was working the lag and impossible to pass when he used a defensive player). So I worked with a friend to get some pingtest numbers to see what is happening. The first thing to understand is the ping times (time taken for internet traffic is different and primarily based on geography) and also to a certain extent on the players own connection speed and internet backbone in their country.
These were times I found in my test.
US West Coast to US East Coast (100ms)
US West to Europe (250ms)
US East to Europe (100ms)
Europe to Australia (400ms)
US West to Australia (300ms)
In general you will experience a lot of lag when playing players from Australia (and it is not just because the connection is slow on the other end). The traffic has to go through various hubs to reach the destination.
The lag does cause freezes when playing from Europe to Australia and it can affect your play and concentration.
I think the fact that Australians lag against everyone else means they cope better with lag because of more practice with lag games. I suspect 90% of their games have large amount of lag in it.
We also found that who sets up the connection affects the lag benefits to a little bit but not to the extent of geography. This might be a wii GST thing though.
As to who has overall benefit from lag, it is inconclusive, and in my opinion subjective. If you play most of your games lag free and then play an Australian with heavy lag, you will be frustrated to the point where you feel the other guy has some advantage. But I could be wrong, maybe the lag benefits go indeed to the Australians
