I definitely prefer the 600 to the 595. The 600 is colder, has more impact believe it or not, has a more coherent sound without any grain, and more lushness in the midrange. The 595 is more upfront, has better bass resolution (the 600 has overly liquid bass but it sure does kick), and is warmer. I'd recommend the 595 for rock over the 600, and of course if your amp can't hack the 600, then it's an easy choice in favor of the 595. For classical and electronic music, and especially trance, I'd recomment the 600. It's really awesome for psytrance! Strong, kicking bass, sharp, detailed treble but not all that fatiguing, and a great, coherent soundstage make well-recorded psytrance a real trip.