Just an update on this, the annual Crossfit Games are going on right now and "Murph" was one of the workouts for the individual Men and Womens categories this year. They completed the exercise wearing a 20lb weighted vest and broke the Pulls ups, Push Ups and Squats into 5 rounds( 20 Pull, 40 push and 60 squat each). Just to give you an idea of how elite these competitors are(top 40):
Mens 1st place- 34:38 (23 mins faster than me haha)
last place- 51:04
Womens 1st place -36:42
last place-53:40
Jeff