what matters is results, my arms were not growing when I was all caught up in chasing the pump, using light weight with perfect form, and then I wondered how come my arms were stuck at 15.5''. Once I understood that high intensity and going heavy, and getting progressively stronger is what really matters, my arms blew up to 20''. also it's important to do heavy cheat curls and stop that nonsense of ''good form'', it's all about getting stronger, form can be a bit sloppy if you truly want to grow, perfect form is nonsense