Matt,
I am interested in knowing why you would not like metal played on a system that reproduces it accurately, like the Martin Logans and monoblocks.

When I first started listening to music, it was on AM radio, and every improvement in actual reproduction quality made the music sound better, with the exception of most of the bebop records made with about zero budget in the late forties -- they had poor bass and generally were done by someone who forgot to mike the drums!

The only sounds that sounded WORSE on better systems were things like the on-purpose distortion in Creedence Clearwater guitar sounds...which were okay to sound worse because, hell, that's how they wanted it to sound, and the idea was to have a dirty sound.

Now, if your metal sounds worse on high quality equipment, that tells me that it is not well recorded or that you really can't stand to hear it -- you really just want to hear what you think it should sound like.

(I remember a music instructor telling me that Ornette Coleman's godawful alto sax sound came from him listening to music on a shitty* record player, and then playing to make his sax sound JUST like what he heard!)

High fidelity means being highly true to the original. Good or bad.

*do not take offense: this is a technical term.