I have one and used it today. My dog wears a walking harness, btw, not just a collar. While I like the control a regular leash gives me in crowded situations, it’s great for walks here near the house. We don’t get much traffic on our street or the next one over, so I can relax and bit and give the dog a bit more room to roam on its own. She loves to sorta zigzag back and forth across the street, which works in this location, without me having to zig and zag with her. But, if needed, I can, so to speak, reel her in easily. I will note, too, that I bought one designed for dogs much larger than mine, so it’s essentially a strap, not a cord, hence easy to grab with the free hand, too, if necessary. Fortunately, given my relatively traffic free area, I’ve only had to do that a couple times but it worked fine as the nylon strap/band was easy to grab and hold. Again, while I prefer the leash at the park when it’s crowded, the retractable one has its value, too.