It's amazing how much investment, technology, and care actually went into making these cars. GM spent about six billion dollars to create Saturn, completely from scratch; the engines, chassis, design, interiors, and many other parts, as well as the Springhill, Tennessee factory, was completely unique to Saturn. These cars had build quality, fit-and-finish, and refinement that was better than any of its Japanese competitors, save the EG Civic. They were a far cry from the Cavalier or Sunbird. People who bought the original Saturn cars were very satisfied by them and took pride in owning a Saturn. Even being pricier than any other non-luxury compact car, and that Saturn was not known as a brand very much, the S-Series sold on average 200k-300k units per year, for the first generation. The main criticism of the first-gen S-Series was that the exterior styling was kind of dated (after all, the design did date back to 1985), and somewhat on the ugly side. I personally think the first-gen S-Series is a decently good looking car, mainly because how radical the styling was compared to its competitors, let alone other GM products. Though it does kind of look like a miniature version of a 1990-1997 Oldsmobile Cutlass Supreme from some angles.
Of course, where Saturn went downhill is when GM threw less money at the brand. Some GM execs believed that far too much money was going to the Saturn project than was necessary. So, when GM slashed Saturn funding, you saw a second-gen S-Series that was arguably worse than the first-gen, and quite dated by the early 2000s, as well as boring rebadges of other GM products such as the L-Series and Aura (Vectra), Vue (Captiva), Relay (Uplander), Sky (Opel GT), Astra (Opel Astra), and Outlook (Acadia). The Ion, the only non-rebadged Saturn other than the S-Series, shared nearly all of its parts with Chevrolet and Pontiac products of the time, and was known for having an atrocious interior design. Such an uninspiring array of cars is the reason why Saturn sales slumped. Why buy a Saturn when you could just go for an analogous Chevy or Pontiac that's likely cheaper, anyway? For the 1st-gen S-Series, there was nothing quite like it compared to other GM products, and that's what makes it so special. Hence the brand's slogan, "Saturn: A Different Kind of Car Company".