Ryder, given your last disclosure, it would seem that you already have a pretty good idea of what to think about about that person's opinion. A dealer with strong opinions who 'strongly advocates' what he carries is, well, just that. If you believe the power cords sound better than stock, it's what you think which counts. If he is willing to back that strong opinion with a 3-week in-home demo of the ICs and SC he carries, well, that might be an interesting opportunity. If at the end you think it is worth changing, you learned something. If not, you learned something too.
What you have is a "Dear Ann Landers" situation, where Ann would say some combination of the response on the order of "Some people are rude and are just that way. If you don't like their rudeness, stay away from them." I would add, if you can make use of their opinion, why not get something from it.
What you have is a "Dear Ann Landers" situation, where Ann would say some combination of the response on the order of "Some people are rude and are just that way. If you don't like their rudeness, stay away from them." I would add, if you can make use of their opinion, why not get something from it.