I asked two trainers who work with pro players about CF. They absolutely do not recommend it during the season, and only recommend some of the CF exercises during the off season. Any good trainer can design a safe beneficial 30 minute cardio workout using sit ups, pull ups, push ups, squats, running, burpees, and some neutral weight lifting. But racing to do a certain number of exercises within a ten minute time frame for a personal record seems like a recipe for form breaks and injuries to me. I thought my one CF workout was okay, but the recovery time for me was over a week and that just got in the way of my normal daily life. I can see the appeal of it, it wasn't for me, and I would suggest anyone who tries it approaches it with caution. And be ready for the cult like attitude of most of the people in 'the box'.
Pros should stop wasting money on coaches and doctors and just read the experts on this forum.