Based on previous experience i would say your best bet is to call as soon as pre orders go live for T mobile. I've heard from some people that they did in fact get a call back from a rep but I've also heard that they haven't. Me personally i called the past two years as soon as pre orders went live and was able to get someone on the line within a minute, got both of my iphone's ordered within 10 min and got them both on release date. I tried the website but for me at least, it went down both times as soon as pre orders went live.
Thanks for the insight! So, what time realistically do you think you called?