I would only use these in a controlled environment on certain dogs for short distances. Taking your dog outside regularly on a slip lead to me seems to be asking for trouble.

Pros: Convenient

Cons: Unsafe

It is good to have one as a back up, maybe in the car. We used to use them all the time at the shelter for dogs who would be taken out of the building.

Pros: Inexpensive

Cons: temporary use; dog can slip out

We use these for puppies that don't have collars on to walk short distances. Also is good to have in your car for a dog that is loose.

Pros: good for dogs that don't have collars on

Cons: none

Only kind I use...
Great for training a dog who pulls ....

Pros: You have so much more control with this type leash

Cons: None