My previous source was the Oppo DV-980H. I always thought it was a pretty good sounding player, but the 105 is just SO much more detailed.
Yes, I'm using the 105's internal DACs. Right now, running unbalanced to the Headamp GS-X. As soon as I get some XLR cables, I'll have a fully-balanced setup.
It's nice to have only one player that does everything well. Oppo's used to be one of the best kept secrets out there, not anymore tough.