I bought my Cadillac STS V6 around Christmas time, trading in a Mercedes-Bena. Previously, I have had two Lexus GS 300s. The STS is very quiet and comfy. The DVD audio is SLOW to respond to orders though and the voice recognition does not work. Its Bluetooth is reliable. The navigation system is fine, but won't let you use it while driving even if your passenger is trying to use it. Bluetooth functionality is limited while driving as well. The backseat is tight for leg room. OnStar costs a fortune. The trunk is smaller than expected. Having said this, my ownership experience has been excellent despite the flaws. The stereo using DVD audio discs has OUTSTANDING sound quality and will make you really want it. The video image and functionalty of the navigation screen is large but average resolution. The interior ambience with DVD audio is great.
The comfort, DVD audio, seats, smell of the leather, wood steering wheel, large navigation screen, and wide high console for resting arm on. This car is quiet at high speeds and around town. The tire pressure monitors show exact pressures on each wheel. I like the LED tail lights and the keyless entry is a pleasure. The park distance control feature is nice as well.
My gas mileage has been terrible so far, the headlights aren't xenon. I don;t like the limited navigation and bluetooth functionality while driving. The rear legroom is too tight and the trunk is too small. The headrests are not soft enough. There is an ugly cable connecting to the rear view mirror.