The NYC subway system is far from the nicest in the world and it has a lot of infrastructure problems--in part because of its age. But a system that moves about 6 million people on the average weekday can't be all that broken.
Every time I took a cab to an important meeting in manhattan, I regretted the decision. Whereas I've taken the subway to hundreds of meetings/appointments and really only gotten delayed impactfully a handful of times.
No doubt that things have declined significantly in the past year, but I do think that saying NYC is a "driving city" is overstating.