I've seen the best changes in my physique and good muscle growth with high reps G. My focus is on excellent form, full ROM, complete contraction of the muscle and slow and controlled positive and negative movement. Whether it's with my chins, DL's, Squats, Shoulder BB press, whatever - it's the way I train and it's working beautifully for me. I'm still progressive mind you, but the weight is largely irrelevant. You can exhaust and stimulate growth in the muscles through higher repetitions, it's not always about the heaviest weight.
There are many ways to build a muscle, not just one.
Go forth and prosper