The general consensus is that Grado's are great rock cans.
However, I love rock and metal and I also have a pair of RS2i's but I can't stand listening to rock on them. They are just to 'thin' sounding with rock because the EQ on Grado's is biased towards mid's and highs and not enough lows.
This is just my personal preference and just shows that everyone's interpretation of good sound is different and you should listen before you buy to ensure its to your taste.
