your opinion please

I am planning a trip to the Four Corner area this summer and I have been able to set one day aside for a train excursion. I am planning to reserve seats on the D&S mainly because I have heard about it for so long ( I just recently heard about the C&T and had a hard time deciding). Our only experience with NGRRs is the Cass and Mt Washington cog RRs (unless Disney counts.) My questions are....

Is there any reason for me to do an "upgrade" to a return trip by bus? I think I would rather do a round trip.

What type of coach should I take? My wife doesn't do well with a rough ride so I was thinking about the side facing deluxe coach (Rio Grande) or the table and chair seating Prospector.

Anything else I should think about?