Earlier quoted context omitted.
I took the Coast Starlight (connects SF and LA) a couple of times in the past 10 years, and I have had a pleasant experience each time. Food was good and while the train wasn't sparkling clean, at least in the areas I cared about (my seat and car) it was fine. Just the bathrooms weren't great. Admittedly this is a shorter trip than yours; this one is only an 8~10 hours ride.
I've taken the Coast Starlight about 4-6 times between SF (well, Emeryville) and Portland/Seattle. Most were pretty much on time, except for one time when the train hit a person/car on its trip up from LA. It arrived around 5 hours late at the station and ended up being something like 10 hours late by the time we disembarked. It can be frustrating to experience long delays if you have a tight schedule, but otherwise…
Very true. Although I've had some awful delays on airlines as well, and given the choice between being stuck on a passenger train and in a plane, I'd take the train every time. (Though admittedly the airlines have gotten slightly better about not leaving passengers on planes to stew in their own juices on the tarmac for hours and hours. But it took some people really slapping them around in court I think.)