I am probably going to confuse you even more, so I apologize in advance.
I liked my SR60 much better than the SR80 for metal. The SR60 sounded warmer and more whole. I bought an SR225i to upgrade from the SR60 because I wanted more but it wasn't as big a leap as I had hoped. I was expecting to find the heavy metal headphone grail, so to speak. Now I'm selling my SR225i since all I use to listen to metal is my Sennheisher HD25-1 II and HD580.
See, a lot of rock and metal recordings are very sibilant. Most of the bands don't have huge production budgets or are victims of the loudness war and their album's sound is anything but audiophile. A Grado has some pretty brutal trebles that will only emphasize these production flaws. I found them grating and fatuiging with most of my music. Don't get me wrong, there are bands that sound great on my SR225i, but in general I prefer a warmer, less piercing sound for my (extreme) metal.
Actually, a headphone I'm enjoying tremendously lately for metal is my new Brainwavz HM5 (You can also find them as Fischer Audio FA-003 or Yoga CD-880). For some reason I'm liking neutral, closed cans better for metal since their sound is mostly more direct, with a smaller soundstage and more energetic without any direct frequency emphasis. For example, my Beyerdynamic DT880 and AKG K701 all sound too washed out and spacey (K701 especially) for brutal, in your face agressive music. They also sound too detailed (typical DT880) and unforgiving which, again, will only emphasize metal's mostly mediocre productions.