Nick and I decided to take the train up to San Francisco just for the hell of it, because neither of us had been on a proper Amtrack ride before. It was really, REALLY nice. Perhaps you are wondering if you should try out the train on your next traveling adventure instead of flying and driving. Here are some observations that may help you decide.
First, if time is a luxury for you and you aren't in any hurry, then I'd say go for it! Certainly if you are on a tight schedule it would be way more convenient and not much more expensive to fly from LA to San Francisco (and we are flying back so we didn't have to take an extra day), but the time it takes is really the only downside to the train. Fortunately, if you aren't on a schedule and aren't in a hurry, there are plenty of things to do to fill up that time. Also, there's no "get there an hour early and suffer through security" that eats up that time. The train shows up at the stop, you give your ticket and get on. Boom, done.
The seats on the train are comfortable and have a million miles of legroom. There are no rules about bags having to be stored overhead, so you can just sprawl your stuff out at your seat (and if you're short like me and can't actually reach the footrest in front of you, it's nice to be able to use your bags as one instead). There are power outlets at every seat. You can get up and wander around at any time. The windows are large and the views are pretty, and it took me back to memories of being little and staring out the car window on any car ride, absorbing the landscape.
In the lounge car, they have even more gigantic windows and seats facing directly out, in case you are into the sightseeing part. They also have big booth tables and free wi-fi, and several people were just at these tables working away on laptops. One lady had even brought her scrapbooking project, and had her crafts spread out on the table. I think she was working on it for most of the train ride. Nick and I spent several hours at one of the lounge tables playing Magic: The Gathering.
The lounge car also has snacks that you can purchase, and either eat there or take back to your seats to eat. The diner car had some decent food, but that's the only other negative about riding the train - since space is scarce, if you have a party of less than 4, they will seat strangers together to fill up the booths. There is nothing I hate quite so much as awkward socialization with strangers when I'm trying to eat, but if you are an extrovert then this could be really exciting for you.
So, in spite of it being an 11 hour ride, I spent that time napping, gazing, playing Minecraft, Spacechem, Poker Night at the Inventory, playing Magic with Nick, watching a movie, and so on. It was no different than having a particularly lazy day at home, except there was no Mr. Davis to snuggle. When we got to San Francisco at 10:00 at night, I didn't feel exhausted the way I normally do after even the shortest of flights.
In conclusion, if you've never been on an Amtrak trip, and you have some time to kill and are in no hurry, and perhaps have many personal projects that you'd like to get some work done on, then yes, try it out at least once!