I had the same hesitation about mine leading up to the 100k mark (albeit mine is the 3.0 with the GM France tranny). I drive it pretty soft, hardly ever use Steptronic or Sport mode. I replaced my filter and ATF at 100k, and 3k later, no signs of problems. Shifts are super smooth, it doesn't hold onto lower gears as long as it used to, MPG have improved, etc.

So it really is just a flip of the coin as far as I can tell. I believe the ZF trannys (like in the V8s) are a little more prone to failure, just according to my service shop, but there's really no sense in worrying over it. If it's going to happen, it's going to happen, and there's really not any preventatives you can do other than change the oil and filter as often as possible. That being said, I have an emergency credit card dubbed the "double-failsafe card" that will cover a rebuild.

Just my $0.02

__________________
Gone, but not forgotten:
2003 X5 3.0i - 135k - the most expensive club in the world.
Premium, Cold Climate, Rear Climate

Service History

Mods and Retrofits: Satellite radio, MediaBridge, DEPO HIDs + LED AEs, M-B W164 rear-light mod, clear corners, BSW x108 Subwoofer System, illuminated door handles, titanium grill, compass/auto-dim mirror

Traded 9/1/16 -- 5UXFA53533LV80809 -- If you know his whereabouts, please contact me.