Here is the fix: BMW Bulletin #61-15-09. Repair cable part 12-51-7-602-973.

My 09 x5 4.8i now drives like a completely different vehicle. I dropped off a gravel truck and picked up a 3 series! Throttle tip-in is now smooth, shifts are snappy, acceleration smooth and strong!

Hat is off to Carrera BMW, Bend, OR for doing the research and fixing the problem.