Only til it breaks. After that, you get the new '06 dif under warranty, and you're good to go.

Cadillac came out with a TSB to add some urethane bushings to the back end to help with the hop. I had that done, and it seems to have fixed it quite a bit. Also, the car comes with runcrap tires, and they are loud, wear like crap, and contribute to the hop. Replaced them at 8k miles, and it's quieter, still sticks corners, and doesn't hop.

One cool feature is the lateral g meter in the dash. Right now, I have 1.11 left and 1.09 right. I hear they only go to 1.2. Gotta work a little harder.