I love train rides, but somehow, Amtrak is consitently late - and I mean an hour late. The prices have skyrocketed, because there's still no competition, and the Acela just doubles the price of the regular train. Even with the Acela, that train seems to break down a lot. Now, I will say, that's a nice train - whole thing is like being in first class, a very pleasant place to be stuck if you do get stuck.
Otherwise, the regular NE Corridor line is just a pain - always late, don't think the trains have been upgraded for years, interiors are kind of dark, depressing. The seats are fairly comfortable, at the very least, but don't expect a big smile from the conductors - $100 train ride doesn't buy good service.