Just bought my 2005 Cadillac CTS, moonstone/ebony, with every option except navigation. I am very happy with my purchase. I also drove the Mercedes-Benz C320 (too small), the Infiniti G35 (too cheap an interior), the BMW 330i (again too small) and found the CTS to have the most power, the most room, and the most unique look. And since not everyone has one, there is some exclusivity to having one. I traded my 2003 Deville DHS, gave up some room, but gained a lot more sport.
The 3.6L is an amazing engine. I love the wood steering wheel and shifter. The BOSE sounds amazing and the XM has me hooked on commercial free radio! I'm impressed with all the personalization the set up allows for each driver. I love the look of the car.
The interior is a little plain, but you do get used to it. The rear head room is tight, so if you are tall, you may hit your head, my grandfather hates the fact that there is no grab handle over the passenger seat to help him get in the car.