my mum went and bought me one when DD did a bolt in bunnings when I was 37wks pg - she could run faster than I could waddle! Mum's justification was what happens if she runs off, i can't really leave the pram. And, I love it. It saves alot of tantrums and a lot of stress. DD will happily put it on, and she knows that if she doesn't wear it, she has to sit in the pram. I went to th city a couple of weeks ago without it, and even though my mum was with me, it was so stressful that I didn't enjoy it at all. I find it gives that bit of security when its needed, so in the city or if we're walking to the shops by the road.