For majority of my trips, there's no time penalty in actual travel time, or it's neglible. I save some time every weekday by not commuting by car.

Being bound to public transport schedules can be a pita, mainly if I'd like to travel late at night / very early in the morning. Also on some occasions, public transportation doesn't go to or near enough my destination. Getting info on more remote public transportation options can be very time consuming and tedious. Not all small local bus companies in the middle of nowhere have great Internet timetable/route services.

--J