But on some days you just can't beat the metro. It is probably the fastest way to get anywhere that is reasonably close to a metro station. It is safer than riding your bicycle or even, perhaps, walking.
The metro also has its own charms, and might be my choice of the day simply because I'm in the right mood for the specific things the underground has to offer such as a variety of architectural styles of station; a closed atmosphere good for reading; and a wide variety of people thrown together from very disparate parts of the city.
The last aspect is pretty amazing. You go so fast from station to station that within minutes you start seeing people from different neighbourhoods: rich or poor; student or professional; young or old. This last aspect is a whole new blog post in itself: how you can tell which stop a given person is getting off at.