Redline has been famous for a long time as a racing oil. As far as I know, it is still used a lot in auto racing, unless (with all that money) people have gone to special formulations for each race. As far as I can determine, still one of the best racing oils, unless people have gone beyond it. According to what I have been able to find out, Redline gear oils are still great, even if the motor oil is becoming dated.
But as a street oil I think there are some concerns. It is expensive ($7.00-$8.00 a quart), not available just anywhere, has not shown real good UOAs at this site in general (although some UOAs with Redline are great), and does not have the API starburst symbol.
However, for a very long time, I have wanted to try Redline. Even more so then Amsoil (I actually did try some Amsoil, but it was XL7500). People say that it keeps engines clean and that engines run real smooth with it. Someday, I do want to try it.