Hold on now. I'd hardly consider this a waste of money. There are tons of members here who can vouch on the 598 sounding better. It might a bit of a dubious upgrade when you already have the 595, but if you are new to the market I strongly urge you to take a hard look at the 598. There are people who hear it, and some who don't. If you want to take the risk you can try the mod for the 558, but last I heard the drivers between the 5x5 and the 5x8 are not the same. As an owner of a 598 I think the OP would be very pleased with these headphones especially considering the music genres he listed.
But zombie-x says he has taken 598 apart and they use the exact same part number for the driver. So WTF???