I was in the same situation as you - bought a 2007 X3 in WA state in September. I took it into the dealer and they will check your software for free - if it needs an update they will probably charge you $130 or so. That was the quote I got but didn't need the update. Instead they just reset the adaptive learning for me for free. The other dealer I called wanted to charge $350 for the update if needed (so they didn't get a visit).
I still find the downshifting harsh at very speed - 3 to 2nd I think is the bad one but you get used to it. Shifting up isn't much of an issue for me anymore but took some time to adjust to that sensitive gas pedal.