if some one asked me,what is better,to do back pulldowns to the front,or,behind the neck pulldowns,i would say,the front pulldowns are better,but i found a way to take the back pulldown movement to the next level and this is how:select a weight that allows you to perform any where from 8 to 10 reps to failure on the behind the neck pulldown,after reaching your last rep immedietly and without changing the weight,start performing front pulldowns,you should be able to squeeze at least 4more reps before reaching failure.do this for 3 sets.
i did this on my last back exercise day,and3days later my back muscle is still sore.