Last week I went down to Washington DC for work. I traveled down there by Amtrak, it was my first time in about 15 years (so pretty much my first time) that I had been on Amtrak.
I got a ride from someone at work up to Penn Station, much better then the subway with luggage! At Penn Station I was able to easily get my tickets for Amtrak using the Quik-Trak system, just scan the email confirmation and it prints the ticket. I was about 40 minutes early for my train and had considered trying to get on an earlier train, but the line was so long for the ticket counter that I doubted I would have time, instead I sat in the seating area and read a magazine. Penn Station for Amtrak is not the best setup, you have to go downstairs to get to the train, which is a bit of a pain if you have luggage and really seemed to slow the process down a bit for boarding. But I quickly found a seat on the train car next to the cafe car, incase I got hungry.
The seats seemed wider with a better recline and more comfortable then a seat on a plane and there is a ton more space for luggage, and to think I was worried about my carry-on size bag! The aisles were much wider then a plane so it was easier to get your luggage around on the train. I also noticed that there was a power point for laptops at every seat, hmmm, this seems better then a plane so far! Also better then a plane was that you didn't have to go through security and you could show up 15 minutes before departure to board. Since you don't have to go through security you can also bring liquids and other sharp objects, like a scissor.
But what wasn't as nice as on a plane is that the train stopped every 15-20 minutes with people getting on a off, of course there were also all the announcements that come with people getting on and off the train. Because of this the train seemed to take forever, actually about 3 and a half hours - a flight is about an hour and 15 minutes. I should say my reading lap wasn't as focused as I find them to be on a plane, but the train generally had better lighting. And well there was no one coming around giving me a drink and food, so pack your own.
The odd thing for me, was that being by myself I felt strange leaving my stuff at my seat to either go to the bathroom or to go to the cafe car. For some reason I've never felt this on a plane. Maybe it's because you kinda get to know your seatmate (at least they become your neighbor even if you don't talk), or because the passenger manifest has their name as being next to yours. Or maybe the fact that you get on the plane and everyone gets off as the same time makes it feel safer to leave your stuff. But on Amtrak people are coming and going at every stop. But I felt odd leaving stuff and that I was more likely to have something stolen. It's probably irrational, but it's how I felt.
I would definitely consider Amtrak again for a trip to Washington DC or to Boston. Though plane tickets are often cheaper, for a short trip with a little bit of luggage Amtrak is less of a hassle, though I think I would look more at the Acela service, it's a bit more expensive but it also takes an hour less. I would caution that I've heard on the late night trains the clientele isn't the highest, so I personally would avoid those trains.