Probably belongs in a museum/collection. My son had one just after he sold his ZX9R and was badly disappointed. He grew up with RD250/400s and had YZ80, CR125 and XR250 when younger, so he had a basis to judge. He modified a few things to try to improve handling and it was still an old bike and not all that fast.
I know that we all want it to be like a street version of a factory YZR500 racer but it's not. Not to say it's a bad bike, but it would be like fantasizing over making love to some beautiful singer/actress/your teacher at high school (insert your own fantasy) only to discover that she's really just an old woman that's not so hot in bed any more. We need to preserve our childhood fantasies, so leave this one in the crate and imagine how fantastic it would be to ride it. reality sometimes comes in a distant second to imagination.