That's awesome. I remember when I wouldn't have been able to do 5 pull-ups in a single day, let alone 50 in one workout.
A few weeks ago for Crossfit the workouts was 100 pull-ups, 200 push-ups, 300 squats. I broke them up into 10 rounds of 10, 20, 30. I forget how long it took 30 minutes? Anyway, less than a year ago, such a workout would have been laughable, really, if you asked me to do 100 pull-ups there would be no way I could do it in a single day. But going through the Simplefit program really made the difference.