I have some body parts that grow from going balls to the wall with horrible form. Just push the most amount of weight I can for 12-15 reps. Back thickness and quads are like this. Then there are other body parts, back width, biceps and chest, where I need complete control to grow. I am sure there are dudes who are like, WTF, that guy is big, but he is barely lifting anything. However, if they came over and performed the rep in the same manner, they would see how hard that rep is with that weight.