Well, the 0-60 time for a 442 Cutlass Supreme in 1985 was..9.8 seconds. That was with the "High Output" 307, 3.73 gears and more aggressive governor in the transmission that allowed WOT upshifts at 4500 RPM. The standard model would have had 2.41 gears (or worse) with a 3,000 RPM governor. If it did 0-60 in 15 seconds, I would be surprised. The stock V6 Cutlass? Well it was a full 5 seconds faster to 60 than a similarly sized Mercedes Benz 240D. Which sounds good...until you realize that a 240D takes 27 seconds to hit 60. So, umm.... yeah. The v6 does 0-60 in about 22 seconds.
The difference between a RWD Cutlass and the Ciera is that the Cutlass Supreme can be improved on pretty easily, while the Ciera was a poor answer to the question the Honda Accord answered so much better. That is, how to make a good, FWD transportation appliance that was comfortable and inoffensive. Very few people today own a G body to just drive it as is. In stock form, they are so bad compared to other cars available today for similar money that you would have to be self loathing to want it to remain completely stock. Fortunately, they are easy to improve without butchering their "Essential Gm-ness" as I like to call it. That is, you can keep the style, and interior but lose the suck. After all, the interior is of a much better quality than anything GM would build for another 20 years, so there is little reason to mess with it if it is in good shape. The look isn't bad, and usually is easily improved with wheels, tires, tint and mild lowering. Steering feel is a steering box swap away, and the suspension can be improved greatly for less than $50. The interchangeability with other GM products is what makes these cars good. Otherwise, they suck unless you have a late turbo Regal.