Some of the Europeans I've run into say that Amtrak's on-board experience compares favorably to what they get in their countries, even if the trains are slower.
As someone who's travelled on more than his fair share of trains in Europeland - at least on the west coast, Amtrak trains are super-comfy. Big seats, loads of legroom, decent food (on the last trip - previous trip a few years ago involved a fossilised, tepid space-burger).
Best of all, there's often a carriage specifically for viewing the scenery going past. Of which there is a lot. Possibly including someone describing the scenery going past. I learned a lot about Mount Saint Helens that way. (Main reason for choosing trains - I fly a fair amount also.) Way better views than, say, the Eurostar - where you never even glimpse the sea you've been under.