Not my car, I'm just borrowing it for a month, but here are my impressions.
It's just over a year old with 16,xxx miles on the odometer. It has many options, such as heated/cooled front seats, heated rear seats, heated steering wheel (), and XM radio with 6-disc changer.
The car that I typically drive is an E46 (2003) BMW 325xi, so the 200-some inch long DeVille is a bit of a change, especially in terms of handling. Parking is always between hitting the car next to you and hitting the car behind you ! The power is awesome though, the 300lb-ft of torque are always ready. Not a huge fan of the 4-speed automatic though, and speaking of which, why did Caddy carry that over to the new DTS when they have 5-speeds and even 6-speeds now? Cost-cutting I assume.
Basically, it's not a performance car, but it's a great cruiser. Very stable on the highway. The steering is lighter than the BMW but not too light like other GM products (like an Envoy I drove). The stereo, while not a Bose, is still pretty good.