Had both 9500 and HD-600, both gone, gave away the 9500 and sold the HD-600 for what I paid, they just didn't get me involved and want to keep listening. The 9500 was just too bass shy for me and the highs got irritating with some genres, the HD-600 was much better but due to treble peak at 4-5khz these were headphones that I could use for any length of time for some genres of music. Very few seem to bothered by the peak of the HD-600 unlike the peak in the HD-700 and HD-800 which bother a whole lot more.
Just give them a decent amp to properly drive them and they will perform quite well, much better than the 9500.