I paid to watch the final of the Australian Open this year and was pleased with the quality. They've updated the technology now to where you can watch on a Mac as well. Cheaper than cable and a guarantee to catch some tennis. Go for it.
Scratch that. Reverse it. You can't watch it on a Mac. Only on a PC with IE, updated windows media player and the latest version of flash. But with these, it works great. You can switch between the main stadium and court one for complete tourney coverage. Hook your PC up to your TV and you're in business. Crack a cold one, sit back and enjoy. I'm watching Del Potro vs. Sweeting now.