I like both, and really think it depends on the situation and what/how it's being used. If we're going on a suburban/downtown walk, Hugo is on a collar. He walks well, it's cute and why put something else on him. If we're hiking or out on a long line it's usually a harness, just in case he gives chase to something before I see it. I really don't want him throwing the weight of his body against his neck. If we're hiking off lead, just a collar.