Is it better to use more weight but less reps to build muscle?

It depends what you want to do. I use a cobination of it. I would so 4 sets of 8 and the last set that you do, you need to make sure that you can barely get it but you can get it. If your just trying to get cut but not big, then just do reps, but if your trying to get big and cut then you need to do alot of weight and about 8 reps to 10 reps and do 4 sets of them.