@igm,
Cats don't roam the neighbourhood when they are on a leash!
That's where the leash bit comes in.
You need to be sure you have an escape proof harness, though,...and very few truly are.
You certainly have to keep an eagle eye out, though, to protect your cat.
I think it's worth giving it a good go, but after trying for a while, if the cat hates it then I think the decision is made.