During the cruising aspect, they came in handy as well. I was much more comfortable than if I had the baby in a carrier (though the latter is a great tool when it comes to fussy baby needing a nap!!). With the Baby B'Air vest baby could sit or lay on my lap in either direction, and when it came time to eat I laid baby in the empty seat next to me, vest strapped in to that seat belt, but I kept one hand on her. So she was safe and I was free to feed myself and my toddler! Hoorah!!
And for older children who have their own seat, check out the CARES harness (at least 1 year old, 22-44 pounds, up to 40" tall) - it'll keep them safer and in their seat!