Those of you that have AmTrak'd cross-country (East-West/West-East), how was your experience?

Not cross country but northeast corridor is fantastic - DC to Boston, ezpz. Faster than flight with the BS you need to do on both sides. Also the stations are in the hearts of the city of DC, Philly, NYC, and Boston - get off the train and walk to your hotel or whatever - it's just the best.