I would rather watch any qualifying match than to see somebody practice, even if it was Nadal. But that's me. I like to watch tennis matches. I understand others would pay to watch Nadal doing anything- sleeping, sitting, stretching, whatever. I've watched pros practice briefly in between stadium matches at the US Open. Interesting, but I don't think practice should preempt real matches. Also, Nadal got to practice on the stadium court on Friday.