AmTrak-ing across country?

I'm looking at AmTrak routes.. and am intrigued by the idea of taking a train across country.

Has anyone done this?

I'm in Western NY now, I'm thinking the best way will be to take the Capitol route- From DC to Chicago, and then the California Zephyr route from Chicago to San Francisco. From there I want to head over to Yosemite for a few nights.

Anyone experienced doing this?

Coach seats are all that's available, so I'm thinking I'll probably segment up the trip and take 3-4 nights off the train to get some rest and a shower. Just gotta figure out what stops will be best for that.