I know I am late into this discussion. I have traveled to Switzerland several times and been on both the Glacier Express and the Golden Pass. I enjoyed the Golden Pass route much more than the Glacier Express. I would certainly not go out of my way ride it. I love the train ride from Visp to Zermatt (I've done it round trip four times). Be sure to look for the half black and half white goats on the left side of the train as you ride to Zermatt.
Using the cable cars to get to the top of Klein Matterhorn is so fun..fabulous views, the glacier palace and walking on the glacier. I like it better than Mt. Pilatus. However, the trip Jungfraujoch still remains my absolute favorite.
Have a wonderful time.