Should I change the Transmission Fluid?

[Gurltech]

O.k. here's the deal.

I am having a hitch installed (thanks for all the great info on this topic)
Now that I have decided that, the worry begins.

Stats:
2006 BMW X5 4.4i 89k miles on it.
Bought the car used from a jeep dealer.
pretty good after market warranty from Chrysler (the warranty actually list what it does not cover, which is about 10 things)

I will be towing a trailer from Seattle to D.C, with a stopover in Dallas (trip is in October)
Lifetime trans fluid has never been changed.

Question: What are your thoughts, should I change it?
Aamco's price is 250.00 to drop the pan replace the filter and fluid including the differential .


My concern: I have never had a car not have tranny issues after the fluid was replaced. But I have had high mileage cars with no tranny issues and never replaced the fluid.


Right now I just have the usual X5 hard shift issues, but just every now and then.


So yes or no on the fluid change?


Also I want to say thanks to all the forum members, I have wanted an X5 since I first saw the SAV. It is not cheap to maintain but you all have saved me a lot of money and I appreciate all of you and this forum!