I bought these drills to make pilot holes for "decking" screws.  There are times when using a decking screw in a particular location splitting of the deck board, or other wood, may occur.  If I think I am in such a situation, I will drill a pilot hole first with one of these bits.  They stay sharp, and have for a while now as I am cautious not to drill into other screws, nails, etc.  They have a combined countersink/counterbore if you want to deeply recess the screw heads.  However, the countersink/counterbore part is clamped to the drill shaft with hex-socket set screws, and they tend to work loose over time.  I find it necessary to recheck the tightness of the set screws periodically.  DeWalt does supply a hex key in the kit to do this.  If not for this, which is admittedly minor issue, I would have given 5 stars.