I find the "Airline Fare List" the most annoying. Almost all of the dates Expedia shows up is sold out or not available. Search engine is slow and the agents on the phone are very poor (worse than Aeroplan regular lines!!).

I recently booked a LGA-YUL-YVR-YUL-LGA (2 stopovers at YUL outbound and return flight) on ITN and it was US$100 less than Expedia.