My dad's into some "train enthusiast" stuff, but it's never really rubbed off on me. However, I don't think I'll ever take a plane into New York from Boston unless it's a connection. Door-to-door, at least for me, the Acela's not much slower.
Flying: Let's say 45 minutes to drive in and park at Logan. Let's say 90 minutes to check bags, get through security, and arrive at the gate in reasonable time. The flight itself is 80 minutes to JFK, or 90 to LGA. Taxi in the airport, deplane, wait for bags - another 30 minutes. Arbitrarily picking MSG as the "hub" of New York, it's 30 minutes from JFK, 20 minutes from LGA. That's a total of 245 minutes, either airport.
Train: The Acela from Route 128 to Penn Station is 212 minutes, give or take. And it's literally part of MSG, almost the same way TD Garden is part of North Station. Working backwards, that leaves me 33 minutes to get from home to the Route 128 station. I'm about 18 minutes from there.
Of course, it depends on where in New York you want to go, but I'm an Acela guy. It's much comfier than a pressurized tin can, too. That said, I'm not sure how I'd fare being on an Amtrak for almost 19 hours to South Bend. Insomniac that I am, I can barely sleep in my comfy bed.
I managed to return my WC tickets because the Bruins box office was having a hell of a time getting the NHL Ticket Exchange to work. There were already tickets on the exchange for sale...kind of annoying to wait for a week and get no information on when I'd be allowed to sell them via official means. Plus, the price point for my seats didn't look good at all...it looks like the resellers won't be making tons, but I could be wrong.