Transmission Question 2004 X5 3.0i

[Mudnyrey]

So I have been reading a lot of threads regarding changing Trans fluid and Filter.
BMW states that it's a lifetime thing, and I've even spoke to a BMW mechanic and other.

BMW sticks with the "Lifetime" fluid and filter without a regular change at 50K or so.
The others say (And I agree) that the fluid like any other breaks down and the filter can only do so much after so long, and changing it every 50k or so.

So here is my concern,
My 2004 has 156k miles on it and it runs and shifts strong. Should I get the Trans Fluid & Filter changed? or should I just leave it be?
I know that if you changed fluids it might do more harm with an older, high milage transmission that has not been serviced as far as I know since it was purchased new.

I'm the 2nd owner of this vehicle and it has always been serviced by BMW.

Thoughts...?

Cheers,

~Mud