I've broken off my share of big swimbait fish, but never on just a straight pull. Bass can't break 25 lb.

On the other hand, bass *can* bend hooks on a straight pull, so locking the drag isn't a great idea.

How I set my drag in part depends on if I'm fishing by myself or with someone else who is good with a landing net. If there's someone with a net in the boat you can virtually always get the fish in the net before it starts fighting back, so locking the drag isn't much of an issue. By yourself you have to be more careful and use a lighter drag.