Just bought the 09 with Levinson, Nav, and ultra luxury package in the Matador Red. The thing is gorgeous and fun to drive! I traded in an Impala, so this is a whole different ballgame. Got a great deal since the '10s are coming in. Highly recommend getting the Levinson.
Navigation, Levinson Stereo, Ride. Handles like a dream and is so comfortable. The panoramic roof with the two sunroof option is cool too.
Nothing so far! Well, they did get rid of the tape deck in the '10s so that fixed that minor annoyance...