Maybe "bright" wasn't the correct term. At louder levels and with more complex music, everything gets congested and a little hard to listen to. This definitely did not happen with the TacT in the system.
I did not notice this with the latest DAC1 USB. The USB does have an upgraded output stage, which should help and make it worth another listen. If you like the Tact so much the decision should be easy - worst case get a Mac Mini with parallels or Bootcamp to run the room correction software. And then use the Mini as music server ;)