Transmission replaced at 80,000 miles due to "shudder" when shifting from 4th to 5th gear.
I have been very pleased with the quality, ride and handling of the XG.
When carrying four adult persons, the car will tend to "bottom out" on rough roads.
I too had (and continue to have) a tranny problem. Mine is from 3 up to 4. I have had one tranny replaced (I am sure it is a computer problem.) I also have a near-death experience with hard acceleration from a stop within the first 5 minutes after starting the car.