Nathan and I both agree that not having a car to think about and worry about is nice. There are days with the kids that it would be handy. But overall I like the exercise of walking.
The double-decker buses I have to watch with the kids, as they don't stop for you to find a seat, so I have to try to get the situated otherwise they can get jostled about. Jane calls them bunk buses. The best feeling of all is arriving at the bus stop just as the bus is coming in, getting down to the platform just as the subway arrives. You feel like you won something, or accomplished some great task.