I have found that the maintenance practice which has the greatest effect on fast and firm fairways is hollow tine core aeration.
Below the surface of the turf there is a layer of thatch. Thatch is what makes a fairway soft. Even a dry fairway can be springy if it has an inordinately thick layer of thatch below the turf, although it is unlikely that you will encounter a dry fairway on a thick layer of thatch, because when fairways get thatchy you can't allow them to dry out or they will die.
All things being equal, thatch management is the key to fast and firm, and aeration is the best tool for dealing with it.
Excessive layers of thatch come from excessive fertilizer applications in the pursuit of a lush green Augusta-like appearance. But even a moderately fertilized fairway will become thatchy if it is not core aerated annually.
The dirt that is brought up from the aeration is chopped up and brushed back in to the turf, and this acts as a form of topdressing, which dilutes the thatch, and helps it to break down. Also when we bury the thatch with dirt, we may cut tighter without concern of scalping, giving us more roll.
If you aerify in the month of May you can throw some newer improved varieties of bentgrass in the holes and you will improve the drought hardiness and disease resistance of the turf.
Core aeration opens up channels for water movement through the soils, to gives us greater uniformity of moisture control. There are places on our fairways where the percolation rate of the water is, let us say, two inches per hour, compared to a spot ten feet away that is less than one quarter of an inch per hour - all of this in the scope of one sprinkler which covers a 90 foot radius. There are variations in the soils which must be made uniform to achieve effective moisture control, and aeration is the best tool to address this problem.
The caveat is, golfers are generally unhappy when we aerify.