The scenery is one of the most attractive parts of this type of travel: you really feel like you are traveling. A sharp contrast to the experience of flying between these places. The most gorgeous scenery we passed through was on the stretch between Denver and San Francisco.
There is another aspect to this. No one wants to live next to a railway line. Traveling this way, you get to see some of the worst poverty of the US. This is an education: or it was for a European couple used to experiencing the US through the lens of Hollywood. You get to pass through one-street towns, shacks, unspoilt forest, very much spoilt forest. A different landscape of America.
In conclusion, I would very much recommend this. But it's not for everyone.