I think if you understand the commitment of owning a dog, then a cat isn't very different. Personally, I think it's easier to own cats than dogs, since they are more independent and require less attention. (Dogs require walking, are generally much more dependent on affection/attention)
Cats tend to be more relaxed. You have to earn their love and trust. Some people really hate that, others find is extremely rewarding.
I love my cats a stupid amount, but they still drive me crazy. They have ruined pieces of furniture, continually tear up my flower beds, always manage to plant themselves in front of my feet whenever I'm carrying something heavy and unwieldy, and seem to always be meowing for dinner.
I also really disagree that you can't have a safe indoor/outdoor cat system. I'm super paranoid about my cats being hit by a car, even in the suburban quiet street we live on. But, we never let the cats out the front of the house, and they don't stray enough out the back to make it onto any roads. We don't let them outside at night or when we aren't home. We also make sure they are up-to-date on all of their shots. Our cats are so much happier when they are allowed outside, which in turn makes for a much happier household.