But what should I be looking for? The one that flies the straightest with the least flexing? The one that impacts the center of my aiming point? From how far away?

If I use an inferior CE terminator (not select) from Wally world to do this test, should my results carry over to the selects? I ask because I can get one of these right now, cheap, but I'll have to wait a bit to get to a shop that sells the selects.