I have small flexi and it save me my baby from being lost. One time I got distracted and Tommy pulled me hard and I lost grip on the handle but thanks to the fact that it is a big plastic handle and make noise on the ground he did not run away but stopped and I was able to catch him. Next time my daughter dropped it and Tommy stayed still waiting for us to pick leash up
Once he tried to escape on a regular leash and my daughter and I had to run after him through the whole neighborhood. That was scary. Now Tommy is older and does not try to escape that much. I'm happy with Flexi. I upgraded to the model where handle is made of rubber and don't have anymore problems with loosing grip.