In my opinion a g68 is a 568 with a boat load of connections and room correction.

Don't even consider either if you are thinking of adding a different DAC.

I've owned both as well as an 861v4.

If you are hooking up to analog the more balanced outputs the better. 568 is limited to 3 and depending on g68 model you get none or 8. That will make largest difference.

- Fiddler (IMHO)

If you think listening to music is fun, try learning an instrument.
HT: G61RSL, 4x5K, 5.5KHC, 2xSC6000, Transporter, HD621, Philips BDP7501 4K, Tivo, 65" LG OLED 4K C6
Computer: Foobar2000, 5K, Mojo, HiFiMan HE1000 V2