Pretty straightforward route. 11 hours of travel and 172$ per seat in couch vagon. Considering that I wanted to take my whole family to this trip it just doesn't make sense to go by train. Car is going to be faster and cheaper even considering parking fees in Boston.
Sometimes going by train is just more pleasant. Kids don't need to be strapped into carseats, repeatedly asking "are we there yet?" You can go to the bathroom or stretch your legs any time. You can do other things, such as enjoy the scenery or read a book. Also, last time I checked, trains are lot safer than cars. There is no traffic. Finally, you don't have to drive!
If you like, you might consider soft factors in addition to the fare :)