Cats are good pets.
I have a dog AND a cat, and they love each other, truly. But the cat does have a way of getting under the dog's skin once in a while. It's like the baby brother that knows exactly which buttons to push, and how often, to get the EXACT amount of irritation desired. A couple of times a week there's a noise like a zoo explosion as the dog tries to kill the cat for about 4 seconds, then gives up when the cat escapes to a counter or appliance top. 30 seconds later, it's as if it never happened.
The cat is my first since I was a kid, and I haven't been a kid (physically) since before VCRs existed. I didn't want the cat, but my son obtained it as a gift for his fiance when it was just a few weeks old (the cat, not the fiance). Very cute (both cat and fiance). I thought I had horrible allergies, because a previous girlfriend's cat would cause me no end of grief some years ago. This one, though, did nothing to me. I could scratch it, rub my eyes, and nothing. It was like a miracle! Anyway, the kitten scratched the fiance, and she didn't want it any more.
The cat is now de-clawed and snipped, and is a very good pet. He's an indoor cat, not allowed out. With no claws or gonads, he wouldn't last long against "whole" cats. He thinks I'm crazy, though. The last thing he sees before I leave for work is me putting on shoes. The first thing he sees when I get home is me taking off shoes. He looks at me like, "What's up with that?"
When I let the dog out for her yard business, she comes back to the door and barks. The cat will come find me, give a certain sound, and lead me to the door, whichever door the dog is at, and reach up and touch the knob.
The cat could care less about noises outside, the dog trembles under the bed during a thunderstorm. The cat loves to sit in the window and fantasize about chasing birds. The dog loves to sit in the window and bark at anything that moves. The cat loves to sit in my lap and sleep while I'm watching TV. The dog loves to run the cat out of my lap and take it for herself. The cat will sit on the dining room table and watch me eat, with a look that asks, "How can you put that crap in your mouth?" The dog jumps up and down next to my chair and barks for morsels (and gets none - never feed a dog people food) until I kick her outside or lock her in the laundry room. The cat runs from strangers, people visit 5 or 6 times without believing I have a cat. The dog can't get enough of new people, and new visitors put off by dogs don't return, and never get to meet the cat.
They both hate the vacuum cleaner, but no other appliance (washer, dryer, dishwasher, coffee grinder) bothers them.
As for killer instinct, both dogs and cats are killers, but dogs can't catch anything by themselves, it takes a pack to make a successful hunt.