I use Kayak and Google as starting points for every flight search, and I still spend hours and hours finding good fares on good routes. This is just anecdotal,

I use Kayak and Google as starting points for every flight search, and I still spend hours and hours finding good fares on good routes. This is just anecdotal, but if neither Kayak nor Google gets it right enough for me to use them end-to-end, I suspect there's a lot of room for a high-touch, human-intervention kind of searching.