I recently purchased an Eximus DP1 to pair with my TH900's. As this is my first step towards a high-end system it is difficult for me to speak with authority, but I will do my best. I would say that the pairing is truly fantastic as the DP1's more forward mid presentation addresses the slightly recessed mids of the TH900s. I have found myself staying up till 3am most nights as I cannot stop listening to my music collection. The DP1 compliments the soundstage of the TH900's by giving each instrument its own space and the imaging is really well defined. In Daft Punk's - Giorgio by Moroder (88kHz/24bit) the bass is soul shatteringly good. The TH900's just seem to laugh at every bass test track I put them against and this song shows how they can deliver serious bass and not lose clarity in complex passages of music; things are nice and tight. I have also found that the highs are very well controlled with the DP1, which has meant that some tracks that I have previously found a bit harsh are now smooth all the way to the top and sibilant tracks are tamed. When it comes to details I would say this: I have a particular favorite album that I have listened to countless times over the last 14 years but through this setup I am hearing things that I have never heard before and the music has a much greater depth that for me it was like I was listening to it for the first time.
To sum up I would say this is a really solid paring that counteracts the slightly recessed mids of the TH900's and results in a spacious, euphonic sound with tight bass that will rattle your ancestors.
(MBP >> DP1 >> TH900)