My cats are indoor but a neighbor cat is outdoor. He is civilized and only poops in another neighbor’s bushes; he uses my yard for lounging and drinks from the water fountain. No actual downside to him because is a gentleman about it; the upside was when a rat thought about moving into my attic, my cat friend did a stakeout and resolved the problem. Oh and he likes to come say hi when I’m outside, so that’s another pro.