#1: All-in pricing that allows you to specify elite status, number of checked bags, etc., and factors in all the new airline fees in the airfare listing. Obvious benefit there to overcome the limitations of sorting flight options by base fare when the out-of-pocket cost is much higher.

#2: Departure & arrival times as "hard" parameters that won't produce any results outside those times. This is helpful when booking weekend trips to depart just after the workday ends on Friday and return just before the workday begins on Monday. It could also be used in reverse, to list only flight options that arrive prior to (and depart after) a meeting or other important event.

#3: Sorting of flight options based on FF value (cost per FF mile earned).