It was your post that got me going on the C270 anyway..had been wanting to upgrade and when I found one only a year old for $350 delivered I was all over it.
It's like Mantis was saying guys..speaker wire and cables are like chemistry some mix better than others with equipment, no 2 amps/speakers will sound the same with different cables. Just because a particular cable sounds harsh or flat, doesn't mean it's a bad cable, just means it doesn't match well with your system.
Unfortunately it is very hard to test all your equipment with several cables..just have to do homework...know what kind of sound/tweek you are looking for. In my case the Kimber 4tc's were fatiguing with my Oink..which is bright anyway ..I am sure that won't be the same with the C270, am looking for clearer highs, more open and transparent sound.