I really enjoy the Q701 a lot with prog rock and prog metal. I know some, maybe most will say the Q701 is not well suited for metal, but I think they are good with any well recorded/mastered music. They are of course fairly neutral, analytical, and very detailed, so any music that is clipped or has crushed dynamics will not sound that good. The Q701 will not hide the flaws in a bad recording. On a good recording they sound great, and on a great recording they sound magical. I think rock and metal sound good on a neutral, and fast headphone. It's all personal preference though. Some people will prefer a warmer signature like the HD650 for rock and metal, but the Q701 is no doubt quicker and a bit more resolving.
If you are looking for this type of sound signature, the Q701 is a steal at their current price. I got mine for $240 shipped.