Thank you both for your responses. It's good to get some local experienced views.
We have travelled the shorter WAS-NYC leg before via Amtrak and enjoyed it. We splurged and took the First Class option on the Acela and really enjoyed it. We saw a bit of countryside we would not have otherwise seen, and got to experiences a nice relaxed trip between the two cities and avoid and airport check-in process as well so it was a bonus for us.
We are doing the reverse trip again this trip, and just thought we would also do WAS-BOS, but when I started looking at the trip duration I started to think twice which is why air travel came back as an option for that leg. This is the way I am leaning as it is so much faster and when compared to the pricing for the First class Amtrak ticket, flights are actually less expensive.