Their FAQ mentions that if you come on the first train, you'll have to wait for 5 hours, but if you come at the opening time of 10:00, you only have to wait approximately one hour. The fact that people are willing to spend those extra 4 hours to get in early seems to indicate that it provides an advantage to be one of the first.
Incidentally, they expressly prohibit waiting in line overnight. I bet plenty of people would do so if they could.