I only watched the highlights, but it looked to me like a great performance from Paul. There weren't any moments where I felt he was awkward or otherwise reacting emotionally. It looked like he was cool, calm and collected. He explained his positions in an (mostly) understandable and simple way that didn't go over the heads of the audience. He said nothing controversial, but also said some important things that would make someone consider him as a candidate.
I think he did well. The only thing that might have hurt him tonight was the lack of time, which he can't do a whole lot about unfortunately. That being said, it sounds like the other candidates were screwing up repeatedly, so that can't hurt...
Frankly, I loved it when he called the rest of them isolationists!