We are debating among different ways of traveling to and from Boston and D.C., and would particularly appreciate hearing from anyone who has taken the Amtrak regional. What was the experience like: comfort, timeliness? Is it worth it in terms of comfort to pay more and take the Acela? What about buses? We're pretty knowledgable about air travel, but not so much about rail and bus(except for local commuting) within North America. Thank you for any help on this.