Another issue with G68 that doesn't seem to get much discussion is the 2nd zone doesn't work for a different source say SPDIF if the first zone is using an HDMI input through the HD621. As I understand it, there is no fix for this but I do think it's a real shortcoming of the HD621 solution and makes the choice between a G61 and G68 more marginal -- most significant remaining G68 advantage balanced outputs.