Recently did Amtrak cross country for a month ($500).
I wouldn’t do it again for one reason.
Most employees behave as if they never sleep: extremely confused and depressed, unable to form complete sentences. That’s not an exaggeration. I sympathize deeply but it also ruined my trip.
P.s. for the Bay Area crowd, I do recommend the Tahoe route (zephyr) bc it’s more scenic than the purported most scenic parts of Amtrak. And close enough for a day trip.