I got to see him play in LA at Beyond Baroque in Feb 2008. It was such a fun concert, for so many reasons. I've never seen anyone so serious while playing noise - he was incredibly intense, as was his music! Daniel Menche & I were worried that Damion Romero's PA was going to catch on fire - thankfully it didn't! (The red glow coming from the speakers turned out to have been an actual light that turned on when the levels got really high.) He kept trying to make it louder and louder, and Damion kept having to protect his PA. Eventually Zbigniew gave up, but we were all happy with what we got to hear & experience. Probably the most convincing laptop performance I've ever seen - he was so caught up in the noise that the audience sure didn't care!
He was a really nice guy and invited me to a lecture/Q&A that he was giving at UCSD for Miller Puckette's students. It was a couple of nights later & I think Damion, Daniel, and myself were the only folks there who weren't students. I couldn't quote anything he said, but it was still really inspiring. What I remember is how much noise & experimental music clearly meant to him, and how it had to be heard "just right." (The examples he brought sounded awesome on the mutli-channel sound system in that lab.)
I regret that I wasn't able to go out to dinner with them that night, but I'm glad that I was able to spend the time with him that I did. He was a truly dedicated and inspirational man.