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 I think it makes the most sense to just relax and enjoy the view.

I'll be taking the California Zephyr (Chicago to Emeryville; said to be one of the most picturesque routes) this May, which I'm quite looking forward to. It will be my first time riding that line, and my first time in a sleeper.