I had better results with a pair of Castle Isis speakers by replacing the gold plated jumpers with short sections of the Kimber speaker cable that I was using at the time. The sound was more open and detailed. I used a bare wire connection for the top and a banana plug for the bottom on the jumpers and a bare wire connection on the bottom for the speaker cable itself (spades would be the same if you don't like bare wire and should be easy to stack). Mapleshade sells jumpers for $20 (I believe) that are made of their more expensive Mikro line cable. Maybe search under "jumpers" as there is some info in past threads on this. If you were careful not to short it out, you could probably use 26 gage solid core silver wire (without any insulation).
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!!!