I just got the Beyerdynamic T1 and MF M1 DAC yesterday. I would be equally interested to know the DAC that significantly outperforms the Musical Fidelity M1 DAC. The MF is an interim solution for the headphone setup as music listening is mostly carried out in the main loudspeaker-based system.
The Weiss units have been recommended by few friends. The mid-range models should be quite close to $2000, the higher models perhaps slightly more.