I tried it, the first week it was intense. The next day my tris and bis were sore as hell. Then my chest etc...
The next week I tried it again and not so much. By the third week it just got boring as hell banging out 7 sets of 12 reps of the same weight and same exercise.
in the end for the guys claiming shit about it, it's all about the drugs they use. Forcing them to do 7 sets instead of three is not rocket science.