Pros Fast, Comfortable and full of gadgets
Cons Little storage space
Summary I have owned my STS since March and I love it. The car handles beautifully and the ride is very comfortable. It is truely luxury and power combined. Passing other cars when necessary is never a problem.
While it is true that the gas mileage is poor in the city, once you get on the highway it increases to about 24 mpg. Besides, complaining about the price of gas for an STS is like buying a huge house and then complaining that you have to hire help to keep it clean: if you can afford the car, you can afford the gas.
The trunk is a bit small and the glovebox is a joke, but being able to find my way through any city, having my cell phone ring through my speakers and hooking up my ipod without any aftermarket alterations, more than make up for those shortcomings.
I would recommend this car to anyone. It makes driving fun.
Pros One of the best riding and handling cars I have owned.
Cons Cadillac got in over their head with the software and doesn't know how to support a sophisticated luxury car. Very poor quality control.
Summary I have had numerous problems with the nav system, blue tooth, keyless entry, tire inflation monitoring and voice command. Cadillac service centers are able to replace parts but neither the dealer nor regional supprot have been able to correct issues. I have had the car for less than a year and have had the car in the shop for about 25 days of that.
Pros Power elegance, and style that stands out from the crowd!!!!!
Cons none at all
Summary The best sports sedan it stands out from the crowd and GM has done evrything right, from all of the electronic gooodies to the powerful V8, even the v6 has plenty of power.
Pros Performance, Handling, Style, Comfort
Cons non-intuitive navigation system and user menus
Summary My STS has every option available (and a $66k original sticker). With most cars, you can just hop in, figure out all the controls in a few minutes, and feel comfortable. Not so with this car. It has a half dozen "international symbols" that I've never seen before. Trial and error is helpful in figuring them out. The voice recognition system often interprets your command as something totally different than what you wanted.
On a single 4-hour trip, I managed to change the default language four times, by experimenting with voice commands the car didn't recognize. Changing the language also changes the language of all the menus. If you find yourself with German menus, you must know how to say "select language english" in German. Or, you can go through dozens of menus and stumble upon the option to reset everything to factory defaults.
I've worked with four other nav systems, all of which have been intuitive and easy to learn. This system is much more complex and less intuitive, though it has more capabilities than other systems. Even after reading the manual, I still haven't gotten the system to store my home address. I have a degree in mathematics and 27 years professional experience with computers and software design, but I'm far, far, far from mastering this system.
Technology aside, however, this car is a joy to drive. It handles as well as the BMW 740 I used to own. Its power and shifting are also comparable to the 740. The handling is superb and sporty, as is the steering. I feel very safe in this car, knowing that in addition to the advanced suspension system, the car also has AWD, traction control, stability control, automatic level control and ABS brakes. The car shifts when it should, downshifts when it should, and inspires confidence in its driver. The seats are adjustable in every way imaginable, including lumbar support that can even be moved up and down to hit the part of the back you choose. Heated and cooled seats, heated steering wheel, and a great memory system for two drivers. The intellibeam high-beam control keeps the high beams on whenever possible, automatically dimming when it detects headlights or taillights of another car. It sometimes dims the lights a second or two later than an alert driver would do, but all things considered, it works very well.
The adaptive cruise control works nearly perfectly as well - slowing the car when approaching slow moving traffic, then resuming the set speed as soon as the road in front of you clears. I really like the heads-up display (HUD). It appears to hover in the air above the car's hood, and is adjustable in position and brightness. In addition to always showing your speed, when the navigation system gives a new command, the specific command temporarily shows up on the HUD until the maneuver is complete. Changing to a new radio station or to the next song on a CD also displays a temporary informative message.
When the front sonar detects a car directly in front of you, up to about 300 feet away, the HUD will display a car icon. When displayed, you know that the STS will keep a safe distance from the vehicle if cruise is engaged. The STS will flash a red emergency icon and sound a loud beep if it determines that you are getting too close to the car.
Don't expect a soft, floating Deville (DTS) ride on the STS. My STS has the magnetic ride control and I would describe the ride as sporty rather than luxurious. I had expected the ride to be softer under normal driving, with instantaneous stiffening of the ride under emergency maneuvering or hard cornering. Instead, it provides a fairly firm suspension at all times and provides instant stiffening when required. Windy roads and hard cornering are amazing for a 4200+ lb car.
The bottom line with this car is that it is laden with high-technology that takes some getting used to, but once you've taken the time to learn how everything works, the car will recognize you when you approach it (via the key fob), will set your seat, steering wheel and mirror positions, tune in your favorite radio station, set the AM, FM and XM radio presets to your personal presets, adjust the temperature, heat or cool your seats, and even greet you with your own personal message on the display.
Pros Handling, power, comfort
Cons gas mileage is pretty poor, interior plastics don't warrant the 50k I spent on it.
Summary This is easily the best car I've ever owned, but I wish I would have waited for the 08 CTS. They're the same platform, and the CTS's interior steals the show compared to the STS. It's hard to complain about the interior as I did buy the car, but for a car this expensive I want some leather trimmed dash or something other than plastic probably of no higher quality than what's being put into a Saturn. I shelled out the extra dough for the navigation system so I could get the upgraded stereo, little to say I'm not blown away. I think the Rockford Fosgate in my Nissan Titan sounds better honestly. Anyway, I'm just nitpicking (I'd still be doing this if it were an S600). For the money it's a great car.
PS: They're dirt cheap used, I looked around before deciding to just buy a new one and save myself from the hassle of thoroughly checking out a used one.