Ive been looking into it, and pre-sale in this case may also mean that you get tickets fater..not necessarly the best seating.
Im almost 100% sure they sell a limited amount of tickets for each level and then move on to the next.
So in this case im waiting for the general public sale, you may get better seats.
i read it here- http://www.ticketmaster.com/h/help.html?tm_link=tm_help_header