Using Canon 7D in Ballet Performance

I just recently purchased a used Canon 7D.  My girls will be performing their winter showcase at a theater performing the Nutcracker in two weeks.  For the show, I plan to rent a L series 70-200mm lens. I will be positioned at the rear of a 300 seat theater taking pictures.  In the past, I used a Canon 30D.  In two weeks, I will be using the Canon 7D for the first time in the show for the long shots with the L series 70-200mm and a Canon T3 with a 18-200 for the wide angle full stage shots.  I will use a a high ISO for these shots since the lighting will be reduced stage lighting.  It is my understanding that with the noise reduction ON, the burst rate is greatly reduced.  I am looking for any advise in using these cameras in the ballet performance.  I hope to have a higher burst rate during the show.

Thank you for your advise.