I'm a cat person myself. I would, however, like to have a retired drug dog (maybe military) when my kids are teenagers
I had cats before. I got rid of them because they got territorial with the baby. Tried fish since then, and it was a lot of work and they ended up dying from some extra algae growth that I couldn't control. I'll figure I'll wait till the kids are old enough to pick out their own animals.
But I will say that I think I prefer cats only because I feel like I understand them better. It's funny that when a post was made asking people what they'd re-name Aspergers as, many responses said, Cat Syndrome.
On the whole using the bathroom thing with animals
Cats do generally like to go outside or litter box. Males, however, if not neutered will have a tendancy to spray. Most cats are pretty picky about their litter box (not only with the brand of litter, but how often you clean and change it). If you have too many cats for the space you have to offer, you increase the odds of them peeing everywhere for territorial purposes. I also noticed unhappy cats will use the bathroom in places they know upset you the owner (like if you were gone longer than they wanted you to be). Some cats have been trained to use a toilet, but it is highly recommended that you never train them to flush for purposes of your water bill. Also, to add, in general maintenance, I think females cats are easier to care for. The females are generally more temperamental, but they are also generally more independent and clean.. IMO. Also, if you have kids, I think male cats are better for kids cause they generally have more a tolerance for things that bother them (IMO).
As for dogs, all dogs need to be trained. You really don't have to train a cat, but you do a dog. It's not just the bathroom deal, but you have to train them to not bark when they are not supposed to, etc. The other thing, no matter where your dog goes to the bathroom, you will be picking up the poop (or stepping in it).