I'm an aussie player, but i only ever usually play what would be considered late night over here.
So the majority of my games seem to be in the 300-350ish ping region to US or europe.
Best lag free game ever was a 2v2 me, someone from russia, japan and UK. We were all at 330-350 ping and it was lag free, With the exception of a spike or two. Very courteous gamers too.
What i found funny was that as soon as we were in the game, EVERYONE tried to justify why they should stay even wit hteh high ping, "im japanese cable, this ok?" etc. I.e. everyone had been kicked for "high ping" before.
The funniest is getting in a game with entirely US players in it, trying to blame my 300 ping on the fact the game is playing so slow, without even considering the guy with the lowest ping has a sim speed of -2.
Can't wait till its released everywhere. June is going to be demigod's first great month.