dunno about the xb500, but the xb700 have really deep low bass. not sure if that's what you looking for. Comfort wise, I say that are the most comfortable headphones I have tried. The cushions are large and soft. They do make you sweat after long wear though like any other close headphones plus it has leather cushion. But, I find myself sweating more from my M50. I think it got to do with the large cushion creating less pressure on clamp force therefore making me sweat less in the xb700. From a M50 perspective, I do find them to be too bright at times and slightly fatiguing. But when they were my only headphones, It didn't bother me until I got the M50 when I notice it. Definitely fun headphones for the price and the comfort of them are great. Comfort wise you can't beat them. I've heard grados are good for rock, but I also heard they are uncomfortable. I also heard they are the type of headphones that you either like em or hate them. What I learn about headphones are that no one can tell you what to buy, the only thing you can do is read about the description and hope that it fits your need since there are very very few places that you can try them out. wait, actually the xb500 you can try them out at best buy. My local best buy has them over in the ipod section. you might want to look there to see to gauge. The xb700 should be too for away from those except the bass is probable going to deeper.