The Charlie Card is the most affordable, flexible and convenient way to ride Boston’s subway and buses. It’s also seriously flawed.
I Charlie’d my way to and from work today. That means a bus ride and a subway ride. I appreciated the fact that the Charlie Card system is smart enough to realize that I was transferring, and thus should only pay for the more expensive of the two trips (the subway). I was never smart enough to remember about transfers in the old days when you had to get a special transfer ticket (or whatever it was you had to do).
On the other hand, my journey started by getting on a bus behind someone very confused about the Charlie system. At least on the subway the confusion doesn’t hold up the means of transport, although it may well hold up the passengers.