I am not a big fan of wearing tennis shoes because they always feel like they are squeezing my feet too tight.  I purchased the lock laces and they were exactly what I needed because I could keep adjusting them until they fit perfect.  I just got done with a week long vacation of walking over 7 miles a day, and I credit the lock laces with helping to keep my feet from hurting that whole time, and not spending the day adjusting my laces to wear they were perfect.