wjt3- there is no HDMI connection of the G1, only on the G2/GX series.
It is not compatible with the I2S on the DSD, only as Lightning Link exclusively between the Auralic components. I have an Aries G2 and it sounds fantastic streaming to the PSA Direct Stream dac. USB connection sounds much better than AES. The Aries G2 is a major sonic improvement over the Bridge II. Roon with this combination doesn't sound nearly as good as utilizing Lightning DS. Auralic's OS is very good and the hardware/software combo is rock solid. I stream wirelessly via AirPlay.