Cadillac at one time did represent the epitome of quality. The cars had ample power, were usually exuberantly, often flamboyantly styled, and featuered many technical innovations. Cadillacs had Cadillac V-8s, and used the very best of components from GM's broad, deep internal supplier network. GM components were at one time considered world class. For example, Jaguar, Rolls-Royce and even Ferrari used GM automatics, while Rolls speced GM air conditioning.
In the late '70s, the downsized C-bodies, including the Cadillac, were a great success, while the downsized Eldo also did well, like its sisters the Riv and the Toro.
Anyway, Cadillac is as much a victim of GM's relentless penny wise and pound foolish cost cutting as any division. As a need for product with a more youthful appeal arose, as other, imported nameplates became the aspirational vehicles for generations of younger Americans, GM responded with feeble gestures, like badging the Cavalier as a Cadillac, or baging a pretty good Opel as a Cadillac.
The CTS and the STS repesent serious efforts to revive the brand, and to restore it to a level of aspirational appeal. Does anyone remember the slogan "Nobody sweats the details like GM"? Too bad GM seems mainly to sweat saving pennies, while failing to deliver the kind of reliable, durable car that could revive the Cadillac brand. Oh well, I guess there is at least the Escalade.