I would say that with Mules, you get a really good balanced core guitar sound that isnt too hot or too quiet, which then relies on whatever comes after the guitar to produce the tone you want. I think with the right amp you could easily get foo fighters tones with a Mule set. In the cover band I used to be in I played clean stuff such as Chili Peppers up to rock like Sweet Child O Mine with the LP and it always sounded right to me, and I occasionally play metal at home no problems, just needs a booster to enhance the harmonics, tighten things up and make the input to the amp a bit hotter.