I don't like the vocal style of metal, but impressive guitar work. Metal uses a lot of repeating scales and melodies, so from a classical standpoint, it isn't really impressive, but to play it that fast on guitar is not easy. I've been playing guitar and studying music for 8 years and I find it difficult to play that (maybe because I don't play metal at all, but that doesn't matter). Guitar work from guitarists like Stevie Ray Vaughn and Keith Richards is more impressive because there is more thought put into each note, but metal guitar styles are no piece of cake. Whole different beast.