We did San Luis Obispo to Seattle and it was lovely with the sleeper cars. It is far too long of a trip not to do the roomette, but if you are going first class and have the time, it's pretty nice. The rooms are tiny, but nice and quiet and the dining car food is pretty good. They also have a special lounge car for First Class, which is a great place to relax.
The delays do start to add up, but if you're not in a rush, it's a great way to see a gorgeous part of the country.
We brought lots of books and snacks/beverages for the ride (snacks/non-mealtime sodas are not included in the fare, but there is coffee, juice, water, and sometimes fruit available in the first class cars, but we were glad to have some of our own snacks) and we were very happy.