As for intelligence, I think it it differs. Our cat ain't that smart (but cute nevertheless) and is more submissive than dominant, but our neighbours cat is more the other way around.
Same difference goes for dogs I think. But I do believe dogs in general are better listeners\learners, and more capable of understanding what you say to them.
I defenitely prefer cats though, they just do what they like most of the time and are much less dependent of their owner. And they look cute too
