I don't do "group travel". Therefore, there's little or no agent help in this area. After searching kayak and others, I have concluded this computer search business is too difficult for me. (Not the travel itself)
I am willing to pay extra to have them do the hard slog, provided they know what they're doing, and will actually work FOR me, not against me.
(from mid-west US to VIE to Addis and back, with Istanbul, maybe)