The ZR1 more than any vette made the big headlines back in 1990. Yes, it was overpriced at 60K+, but it set quite a few records during it's time.
I don't think anyone who considered a corvette at the time had an NSX in mind.
The NSX is still the most refined today, even compared to a C5. In 1991, when the NSX was released, it made the interior of a C4 look like a plastic toy. It wasn't until the C5 was released, that Chevy took a huge step toward the refinement of the NSX.
However, from a performance perspective, the ZR1 was regularly compared with exotics at the time. In fact, many publications refered to the ZR1 as exotic as well. In 1990, the standard vette only out out 245HP. The ZR1 immediately trumped it by 130HP at 375.
In fact, if you speak to some enthusiasts, the 1990 was the fastest year, faster than the later models with 405HP. It was approx 100lbs lighter than all other years.
It ran 0-60 in the high 4s (4.7-4.9), but believe it or not, this vette was more of a track car than a drag racer. It set a number of world records at the time, including the world endurance record. The ZR1 ran 24hours straight at 175+mph. The 91 models all came with a special sticker commemorating it as the new Endurance Champ.
If you consider what makes a car exotic, the King of the Hill ZR1 actually qualified. It was produced in very limited numbers. The motor was built by Mercury Marine, not Chevy, and had no resemblance to an L98 or LT1 at the time. The LT5 was an aluminum engine with dual overhead cams, 32 valves and 16 fuel injectors. The function of the engine was similar to the NSX in that it also
changed characteristics over a certain RPM, redline at 7000 (or 7500). While the standard vettes were known for their low end power, the ZR1 was known for it's high end speed. In 1990, it ran the quarter mile in the high to mid 12's, blowing away even a C5, although their 0-60 is similar. It wasn't until the Z06 was released, that another vette finally bested the ZR1 in overall acceleration (and not by much). I have personally driven a ZR1 and many standard C4s, and the two feel as different as two separate cars.
The transmission was also non-Chevy, coming from a German company (I forget the name).
AT the time, the ZR1 was THE track car to kick butt in, as the Viper is today.
Due to it's low production numbers, exotic motor (by the standards at the time), and other factors as well, most publications considered the ZR1 an exotic. It was routinely tested against Porsche, Ferrari, and the NSX. Although comapring it to an NSX in terms of build quality in refinement is a joke, it sure posted some serious supercar numbers at the time. It took a Viper GTS to dethrone it as King of the Hill, and then almost 10 years later the Z06 to do the same.
Late model ZR1s still sell for more than a brand new C5.
Sorry for the long post... just a short history of a car that not too many know much about. It had a far greater influence than many realize.
www.zr1.net is a good resource.