Has anyone tried the new Synergistic Research UEF Performance Enhancer - Ethernet Filter?

I was wondering if anyone has tried the new (and expensive) Synergistic Research UEF Performance Enhancer - Ethernet Filter.  I find that some SR products such as their cable line are nicely effective while others..........well, maybe no so much.  According to SR these things run $300 each and plug into unused ethernet ports to "filter" ethernet signals.  Please weigh in here so I can ascertain whether they are worth a try.  Thank you.