Ibanez Tube Screamer help?

I was thinking about buying an Ibanez Tube Screamer. I heard it is a great pedal to use with a tube amp. I noticed some of my favorite bands use it (Metallica, The Devil Wears Prada, Fall of Troy) and is the main reason I want to get one. I was wondering if you use this pedal with other distortion pedals. It seams like you would have to, to get the tone of Metallica and Devil Wears Prada. If that is what you do, do you use the overdrive on the Tube Screamer with your distortion, or is the distortion off and the Tube Screamer is used as a boost for the distortion. It seems like you would turn the overdrive on because Devil Wears Prada uses the Tube Screamer with a Boss DS-1 and the DS-1 would generally not give the tone that they have. If you have this pedal or know how to use it please reply. If you own it please explain how you use it in your setup.