Update 1: About a year ago, I replaced the PSB with a Paradigm Studio Monitor cc570 version 3. This is definitely better and clearer than the PSB. It should be, as it is significantly more expensive. However, we still had a lot of problems understanding dialog in movies.
Update 2: Removed the spade connectors from the Speltz anti-cables, and connected the bare copper. This resulted in a definite increase in clarity. Much easier to understand dialog.
Update 3: Just yesterday took delivery of a single run of Alpha Core Goertz MI-2 speaker cable for the center channel. I also got some of their jumpers to jump down to the LF binding posts of the cc570, whereas with the anti-cables, I was just using the stock jumpers. I have only yet sampled one movie, but there does seem to be a difference from the anti-cables. It seems like there is more "presence" and "air". There seems to be more high frequency response and it is clearer(is that a word?). I do think this addition has improved the clarity of dialog even further.