The Recovery makes a very nice improvement for me with my W4S DAC through USB even though the DAC has a Femto clock built in. According to EJ they work hand in hand and are designed to work together.
The Remedy is similar but for Coax or Optical. It also adds a Femto clock and up-samples Redbooks to 96kHz. So it makes a pretty big difference for my Redbook CDs. However it is more expensive then the Recovery. Tony told me that the Remedy is one of their most popular items.
So I have USB coming out of my Music Server into the Recovery and then on to the DAC. I have the Redbook signal coming out of my spinner to the Remedy and then on to the DAC. both make a pretty big improvement for me!
Albert, the Remedy would probably work quite well on your second system...