I love this microphone.  I could go on for a long time about its features and reputation, but I'd rather speak about its usability.  Firstly, it is a highly directional mic - don't expect to pick up much from the sides or back of it, making it a great, focused instrument mic.  I also attached a windscreen on it (also purchased from Amazon) and I've found that this mic is surprisingly capable as a vocal mic, too.  Don't be afraid to put this mic in front of very loud sound sources, like amps or snare drums.  It'll handle just about anything you throw at it.  If you're like me and have your own home studio, the SM 57 is absolutely essential.  I don't have too many mics, but the 57 has taken over about 95% of my recording tasks, even replacing my condenser mic for vocals.  I could not be happier with this mic.