Tube DAC Advice Needed

These days I'm doing 90% of my listening through a computer-based system using a Squeezebox 3 directly into my SS integrated (a Plinius 8200 MkII). While the internal DAC in the SB isn't terrible, I'm sure everyone would agree it's nothing to write home about--the sound is somewhat closed in and lacks "midrange magic" to use a cliched term. So I'm shopping around for a DAC with a tube buffer in the $1000 range new or used.

After sifting through the posts and reviews, it seems as though at least three fit the bill--the TADAC, the Monarchy M24 and the Paradisea (or Havana). Unfortunately, all three of these are direct order and therefore I'm unable to demo them. So I'm appealing to fellow Agoner's who have heard one or more of these units for help. What would you say are the relative strengths and weaknesses of each, and which would you recommend? Many thanks!