If this is purely an excursion/joy ride, then of course you'll want to book the train both ways. It's a beautiful ride, though depending on your
departure and the time of year, you might be riding after dark.
If, like many Amtrak riders, you are actually using the service to be somewhere at a particular time, then book the departures that best suit
your travel needs. The previous poster's description of the "full monty black jackboot examination ... and interview" is ridiculous. Yes, getting
off the bus at the border is inconvenient but you have to clear border formalities regardless of your mode. At least with the bus, you only come
into contact with agents once, not twice like on the train. If crossing the border is "scary" then you're probably better off staying stateside in the
first place.