I will be going from NYC (midtown, East side) to the Inner Harbor area of Baltimore on a weekday evening. Cost is not at all an issue; the only consideration is speed.

I can take a US flight that departs LGA at 705p and arrives BWI at 825p, or I can take an Amtrak Acela train that departs NYP at 700p and arrives at BWI at 912p. Given these options, what time could I expect to get to my destination? (I know this sounds like an SAT question, but what I'm really trying to figure out is how long it would take to get to the Inner Harbor area of Baltimore from BAL rail station or BWI at that time of night on a weekday.)
Would it make a difference in terms of traffic if I arrived an hour earlier?