I have met some people once in my country. Didn't look that anxious at all, only I did, especially at the beginning. I think the problem of SA can come in very different levels and varieties, for some it's paralyzing, for others just a little problem that prevents them to fully enjoy social situations.
I think whether fellow SA sufferers will enjoy each other's company depends a lot on this.
As for people that I see around, I only know one who probably has this problem. But then, I don't see that many people lately, and I am always so concerned about myself that I might not spot them easily.