I have used both. Made great gains with both. I think whole body routines have a lot of pluses going for it.
1. The body fatigues as a unit and doesn't fatigue localized to the body part trained. It's systemic. In any athletic endeavor the body uses many muscles to accomplish something. It's never isolated so why train that way?
2. If you use a whole body routine three days a week you gave your body three days of whole body stress to adapt to. Training with a split sometimes you hit a body part once a week. I know there is overlap but with a whole body routine it's three times a week.
3. If some weeks due to fatigue, work or family obligations you can only get two workouts in week you still hit the entire body twice that week. An occasional once a week is still moving forward.
4.If you are an athlete training for say football or sprinting can you really devote your time to a bodybuilding split? Do you really need 4 bicep exercises to be a better wrestler, football player, or a sprinter? It would be better for an athlete to do two whole body routines and devote the rest to training for their sport.
Split routines on the other hand has many pluses.
1. You can do more exercises per body part instead of the one or two in whole body routines.
2. Training is easier doing a split just training back or delts and arms etc. I hear so many say whole body routines are for beginners. Who ever says this hasn't done a whole body routine. They are brutally hard compared to body part training.
3. With a split you can train more than 3 days a week. 3 days a week is about the max anyone can do with a total body training day.
4. For bodybuilding a split is the way to go for most.