Collage seems to have positive reviews of Powerfit:
http://www.collagevideo.com/item.aspx?item=5681
They also give kettlenettics 4 stars out of 5 stars. On principle, I'm not a fan of the idea of kettlenetics but I haven't seen the workout. I have been working with kettlebells for a while and I love them but although kettlenettics using a kettlebell, it isn't a kettlebell workout. I'd hope that someone wouldn't hear about how great kettlebells are and then pick up kettlenettics thinking it is a kettlebell workout. If you are just looking for a workout, then it may be right for you but I'd probably stick with those that have known programs, such as the Firm instructor or others.