We were on our way to the shopping mall when I saw a granny fell down while pushing her grandchild in a stroller. The toddler flew out of the stroller and landed on the floor with scrapes on his forehead. That was the usual stroller with the safety belt secured around the waist. I find that this system is rather unsafe as this incident clearly indicates. I have 2 strollers with this kind of seatbelt. Many times Georgia would try to stand up and she always manages to free herself although the belt was securely tightened around her waist.
Stroller brands like Chicco, Maclaren, Mothercare have 5 point belt harness system which secures not only the waist but also the shoulder region. I find that this prove to be quite effective in child safety. I'm considering getting a stroller which has the 5 point harness system though I've already had 2 for Georgia. I guess there's a lot of experimentation with parenting. A lot of items that we usually get for our child might end up being a white elephant because of certain reasons i.e. safety aspect.
So for new mothers to be or mothers who's thinking of getting a new stroller, I strongly recommend getting a good stroller with the 5 point belt harness system. It's for your child's safety. If possible, also get the same belt harness for high chair.