Yeah, me too FWIW.I went the Cat 5 route for a while. It sounded good to me at first but could be harsh at certain frequencies. I did the whole multiple braid thing that is described on line. Alas, I moved on and am pretty content for the time being.
I won't say that I remember it sounding harsh, but I definitely got better quality bass from other wires.
Amusingly, the internal wiring in my Billfort Altec cabinets is CAT5... I should probably remediate that someday...