Your experience on public transporatation is going to depend on the quality of the system. If the equipment is not maintained, the routes don't go where you need to go, or the schedule doesn't work for you, you're not going to be happy with the experience. On the other hand, if the local municipality has made a committment to, and a reasonable investment in, the local public transportation system, you might be surprised!
Even though I don't use it much, Portland's got a great public transportation system, including bus, light rail and street car, that serves a lot of people, most of whom don't seem to complain about the experience; in fact there are many local advocates working to make the system better; improvements continue to grow the system; and ridership routinely outpaces projections each time a new line opens.