yeah a top change would be equally as good but when the audience is burning your fingers and you get the odd fool who trys to work out everything then i prefer this. As for overkill i not sure about that, its not a hard move, i probably babbled on a bit during the description but its a very easy move and if used with the deck face up makes for a very fast and very effective colour change right in front of the audience, reactions from that are enormous

this is what i usually use this sleight for
Cards can be reversed to the bottom as well using this move so a card can be selected, passed to the bottom and turned oer in the same move, deck cut and then spread to show its now face up.
this is also great for an ambitious card routine, they place their card on top and u pass it to the bottom unknown to them, you then place the top card which they think is theirs cleanly into the deck and then click your fingers or whatever and show it has gone through to the bottom of the deck, quite effective i think and is suprising to the audience as they will be trying to figure how to put it on top so fools them over even more
But yeah i agree with Tenko if you cant perform a DL with ease then go back to square one and keep practising over and over and over until it is fool proof and you can do it with no thought at all. if you would like a video with explanation i will try and post one up this evening.