Originally posted by Metalic Dude
It depnds on what and how much time you practice.

It is a golden rule, whatever you practice, mastering it slowly will give you a greater result when played fast.
I have seen countless students playing what seemed like great licks, but once slowed down, sounded like ****, only because they blurred the whole stuff with speed (even pros, ones with award and stuff like that do it, except they throw in a couple of effects, like wah, reverb etc... Who said Kirk Hammett?)