I own 804s and agree they can sound a little bright and bass shy with the wrong partnering equipment. These are indeed transparent sounding speakers and what you feed them is what you get. As I slowly upgraded my cabling and electronics I found the 804s enhanced the refinement of these changes. Its all about creating a synergy and as you suggested finding cabling, components and even room acoustic treatment, etc that complement and counter balance for a sound you prefer. Consider home audition of the Xtream and other cables if you can. I did find copper cabling more pleasing. I'd also seriously consider looking into other options with your source and amps. As I found these speakers improved remarkably with better quality electronics.
Wadia 861>>Jeff Rowland 201 mono blocks>>804 speakers
with Kimber KS1111 (ICs) and Bifocal XL (Speaker cables)
Wadia 861>>Jeff Rowland 201 mono blocks>>804 speakers
with Kimber KS1111 (ICs) and Bifocal XL (Speaker cables)