The '97 DeVille has a very comfortable ride. It is also very reliable. It has a great sound system -- Bose comes standard, I guess. Its gas mileage is actually decent, considering how big a car it is. If I drive "sensibly," I can get about 28 mpg on the freeway and about 18-19 on city streets.
The reliability, performance and comfort. I'm a large man with a large family, and we can all take worry-free road trips much more comfortably than we have in the past.
I had to replace the alternator -- not bad news for having 109,000 miles. But, it is located at the bottom of the engine block, and very difficult to remove/replace. The last alternator I replaced took my about an hour and a half. This one took me over 4 hours.