In-game, probably. In competitive? No. In competitive, Koraidon is usually used as sweeper, with the incredible move that is Collision Course. However, in-game, (if you even want to use a legendary in-game) it might be a good move. But, alas, you still want a fast sweeper in-game.
So, in conclusion, Collision Course is still better than Drain Punch in every way, in-game or not.