To biwire or not to biwire...?

I know there have been a few threads on this subject and it is a fairly controversial subject, but I have a few specific questions on both ways. First, there are dealers who advertise their jumpers by saying," get rid of those junky bars that come with your speakers and hear what your speakers are really capable of..." For that distance of an inch or two, does it really make a difference ? Secondly,some dealers and /or manufacturers who push the biwire method, recommend putting copper cables on the bass and silver on the tweeter. How does this make things better ? Thirdly, for those with biwireable speakers,who want to run a single cable and put in a jumper,what kinds of experiences have you had with different types of jumpers ? I have a single pair of speaker cables ( AZ Satori) and another brand of cables that tend to lean toward the "warm" side of neutral.If I put in some good silver jumpers, would that give a more neutral tonal balance or would it only emphasize the upper registers ? I have yet to find any all- silver cables that I found natural-sounding anyway.Or would it be better to use a jumper from the same manufacturer as the single run you are using ? I know these are a lot of questions, but surely others without the technical know-how like myself have wondered about these things as well. Thanks for your input.