I have not found EF useful for finding the total fare (I can never work out what the taxes and fees will be), though it is useful for finding the difference between fares in different fare classes.

Orbitz is pretty good, but itasoftware can search for a wider range of routes for specific permutations of carriers, and gives the fare breakdown. Once you have found the routing and fare you want on itasoftware, you can usually find a way to get the same routing and fare from Orbitz.