Unless you have big $$$, I can't see Acela. The problem is pricing. Even factoring EVERYTHING in, its still way more expensive AND it takes longer to take Acela.

Now that night train might make sense, but...give up on Acela. I can't fathom the attraction if you are going DC-Boston.

Independence Air, on the other hand, is excellent. Quick, easy, low stress, and high on flexibility. An absolute winner.