I ride the Cardinal from WV to DC and bring my own snacks. There is a water spout and small cups as well by the restroom on one end of the coach cars. Snackbar is overpriced imho, $8.50 for one hotdog is expensive. I have always had a comfortable trip and the employees are very nice and attentive. I ride the coach class and it is a very good value, I even saved more when buying online from the Amtrak site.
On a 8 hour trip, the coach is very comfortable and you can lean your seat back and lower a footrest and sleep easily.