If you haven't tried it, you might hook up your cables to the top posts and let your existing jumpers carry the signal to the woofers. That way, any degredation of the signal due to the jumpers will only affect the woofers. Imaging, detail, etc. will be less affected.
Custom jumpers?
Are the stock gold jumpers for Bi-wirable speakers any good? I was wondering if short runs of high quality speaker wire between the posts would be better? Of course there is the possibility that I'm a complete weenie who thinks about this stuff too much and I should just not worry about this kind of crap!!!