if your an advanced lifter that lifts with intensity , and your used to any sort of DC training, HIT training, or past failure training. full body will not work at all . even upper lower splits barely work. I've tried it all. if your hitting a max effort set on a heavy push session, there is no way your going to in the same session also hit a max effort set for a pull movement, and then a leg movement all in the same workout. impossible .. if you could actually do it , then your. not training hard enough imo.

however, they work fine for newer lifters, or lighter lifters that prefer long voluminous workouts over intensity. or for guys that are just in a maintenance phase and just going for the pump over going for max intensity and progressive overload .

its just another tool in the tool box to use when the time or situation is right