Glacier express Train trip

Yes, its a pleasant journey, especially if you have sunny weather. Multi-lingual headsets will point out the sights around you. So if you want to go from St Moritz to Zermatt (or reverse), its good way to go.

Thanks! So one rides it one way....then what mode of transportation is recommended to leave either Zermatt or St. Moritz?

By train, of course. Where do you want to go afterward? From Zermatt you back track down the valley to Visp or Brig and catch a train either to Italy or northern or western Switzerland. From St Moritz take the train over the Bernina Pass to Italy, or backtrack to Chur and get a train to eastern Switzerland or Austria.

Kim, forgive me if I am misinterpreting, but it sounds like you think this is a tourist-only train route working in isolation. It is not. You can trace the route on the Swiss rail map here: https://www.swisspasses.com/railpass/overviewmap_en.pdf
St Moritz - Fillisur - Reichenau (or Chur - Reichenau) - Andermatt - Brig - Visp - Zermatt.
All the rail lines shown in red on the map have at least one train per hour, including the Glacier Express route. And at all the places I listed (except Zermatt) you can change onto other train routes.
The Glacier Express is an additional limited stop service that avoids having to change trains en route. You see the same mountains whichever train you get.

When you plan your trip, I suggest you plan all the legs, from arrival to departure, so it makes a sensible circuit, probably all by train. You can start with the map, and then look up all times (and prices) for Swiss trains on the Swiss railways site: http://www.sbb.ch/en/home.html