I purchased my CTS certified used. I was looking at several new vehicles, including both the 3 and 5 series BMWs, Audi. I never even thought of considering a Cadillac until I saw one at a dealership when I was looking at another vehicle. I fell in love with the design. I drove it and fell in love with it. I waited a few months to review it so I could really experience the vehicle. I still love it. It is unbelievably comfortable, has a smooth ride, and tons of features. I buy new cars about every 2 years. I will probably keep this one longer, and I'll definitely consider another CTS when the time comes, which I haven't done with a vehicle for a long time.
Memory automatic seats, stereo (especially XM), styling, safety, room, comfort, OnStar (I love the directions and connections, although I don't use it very often), ease of driving, navigation, good sized cup holders, programmable steering wheel controls.
Blue tooth, change the steering wheel volume controls so you don't turn it up while backing out of a parking spot, ipod connection with a place to hold it (cup holder is really the only place), cell phone connection so the cell phone gets the exterior antenna as the OnStar connection.