Just booked at the last minute. For anybody on the Eastern Seaboard looking at transportation options - I opted to go with a bus, given the relative expense in comparison to trains (which are also notoriously unreliable thanks to our wonderful, forward-thinking political leaders). I found that different companies will have different pickup/drop-off locations. MegaBus will leave you somewhere on the outskirts of town - would take another hour to get to the hotel by public transportation - but BoltBus will drop you off somewhere near Baltimore's Penn Station. There are other options I'm sure, but regardless, pay attention to where the drop-off location is - I only bothered to check at the last minute.