I use Bontrager Classiques (laces), and I love them. Never had any problem with the laces coming undone. If you lace properly, using a loop to lock them down - look up "heel lock", runners use this method to avoid blisters - you won't have a problem; as an added measure, the Bontragers have a snap-shut flap on the tongue that covers the tie.

If you have wide feet, laces make things much more adjustable and comfortable.