Theres two camps. One camp believes beat up ones work better, others believe the not beat up ones work better. I dont think it really matters. If you put the right bait in the right spot at the right time with the right presentation you are going to catch fish.

Some believe the beat up ones more closely resemble the beat up hatchery fish that are stocked. My thoughts on why a beat up one may work is this. Its just like crank baits. You can have 10 identical crank baits but one seems to really stick the fish. That one crank bait just has something that we cant detect but the fish apparently can. Same with swimbaits. There is variation in the manufacturing of swimbaits. Take Hudds. Feel the plastic, look at the body shape. They all arent the same. Nor are their swimming actions. Maybe the beat up ones work better because they just have something about them that the fish can detect. And of course the reason they are beat up is because those are the ones that get bit. Just my opinion.