K.T.
We have an Elmo harness and we do use it. My daughter is a wild child and runs off for fun, ugh. We got it in the first place for a vacation we were taking. All I needed was her bolting in an airport at a layover or worse yet, on the cruise ship! Since then we have used it when she is not listening well and does not want the stroller. It is great for short trips however she will noodle, where she just drops to her knees and won't walk. So we have just gotten an umbrella stroller for when she is like that. If we go to the mall or anything we take the stroller, the big one, as that is just asking for disaster!
HTH
K.